Many thanks for all of the extra replies, ideas and suggestions which are much appreciated!
thanks for your message and re: your comments about the Paramo Quito being baggy & flappy I don't think it would appeal to me either then because it would annoy me on windy days and I just want something that goes over my my existing layer options (but perhaps minus a base layer per the advice from PH) and is then waterproof & breathable. I appreciate that a jacket choice is very personal but unfortunately I don't have many places on my doorstep where I can try lots of different options on and even if I could it's still difficult to get the real world performance appreciation of breathability & waterproofness whilst standing in a shop. Thanks for the tips re: the Gore jackets and I'll look into them but previously the fact that a lot of Gore jackets are black has, for me personally, put me off. Also I also wonder like you if claims of being extremely waterproof & extremely breathable can really be believed.
Thanks for the tips and I'll look to see if the jackets that I consider have vents plus I'll take a look at the Altura one. A long time ago I tried on an Altura Night Vision jacket and just for me I didn't like the fit but they could be different now.
Thanks for your message and following this it does make me think that my desire for a bright, waterproof, breathable & reflective jacket might just be like searching for the pot of gold at the end of a rainbow. However I will look at the Showepass jackets. On taking a quick look at their website perhaps their Spring Classic jacket in red (which is ok although not the brightest colour but better than black) but I'd have to catch it in a sale.
Thanks for your message and yes I'm definitely going to have to compromise somewhere and your mehtod of having different jackets for different conditions isn't a bad one. Ideally I'd like to keep the number of jackets I need down to a minimum but we'll see how the search goes.
thanks for your tips & advice and it's funny to hear that the best jacket that you've had just happened to be found in a Normandy hypermarket and being waterproof for 20 years sounds like you had good value for money out of it.
thanks for your message about layering and the right base layers and I have some merino base layers which I like using.
thanks for your message and after Showerpass have been mentioned a couple of times I am taking a look at their jackets with the Spring Classic one catching my eye as a potential. Re: the Gore Shakedry jackets yes they do seem to get good reviews for being waterproof and breathable but they all seem to come in black (which I think is something to do with the fabric only being possible to make in black at the moment) and if possible I'd like to get a jacket in a brighter colour which is more visible.
thanks for your message and it's not actually my 12 mile commute that I'm too worried about because for the time duration of that commute I can actually live with getting wet (I just wear a brightly coloured & reflective gilet over a jersey) because I have a hot shower at the end of both journeys. I'm more concerned about getting a waterproof jacket to wear if it rains when I'm doing an audax or other long distance ride which is over a longer duration. Thanks for your tips and if everyone tells me that the Gore Shakedry jackets in black are the only truly waterproof & breathable jackets then I'll have to consider one but black just isn't my ideal colour.
Thanks for your message and ideas. Yes one thing I had considered was if for example I did get a Gore Shakedry jacket in black could I put my lightweight, brightly coloured and reflective gilet over the top of the skakedry jacket so that I then have a visible layer on top but I don't know if that impairs the performance of a waterproof jacket by for example preventing water from beading off the surface of the jacket.
Hi brian, thanks for your message and funnily enough a CPT3 jacket had come up when I was searching for waterproof & breathable jackets. To be honest you're probably right in the sense that their jacket could tick a lot of my boxes and perform very well so thank you for mentioning it and giving your feedback on it. Unfortunately it is beyond my budget but it definitely looks like a good one.
Also whilst looking for waterproof jackets I stumbled across something else a bit different and I don't think it fits my bill but it got me thinking slightly off tangent. Basically a little while ago I watched the Hugh Fearnley Whitingstall tv series on the BBC about plastic and the damage it is doing to our environment. As far as I can work out the vast majority of waterproof jackets are going to be made from some form of man made synthetic fibre derived from the petrochemical / plastics industry. This popped into my head when I saw a review of a Vulpine rain jacket which is made from a treated waxed cotton instead. Now I know that cotton production has its own environmental issues including water use and so isn't perfect either but I found it interesting that there do seem to be some alternative fabrics out there being used for waterproof jackets. Having said that I don't think that the Vulpine jacket would work for me in terms of what I want from this jacket because it's not exactly in a bright reflective colour and depending on what you read about it people have views & opinions on how waterproof the jacket is.https://road.cc/content/review/153400-vulpine-mens-harrington-rain-jacket
Thanks again for all of the ideas and tips which are much appreciated!