It's only right when you're younger and fitter(and inexperienced?)that you take on some challenge such as what is proposed. It can be achieved,but I have found that tho many may make the attempt on the road inclement weather,dark evenings, don't make much fun and many reappraise their goals. We must support such adventures tho cos it's better than not trying and then going bonkers.
Given a young body you wont come to much harm. Best give-it-a-go
Budget bike for touring?
Re: Budget bike for touring?
You could have a look at a Ridgeback World Tour, or I think they now call it simply Tour. I had one for 3 years and toured quite a lot with it carrying some big loads and had no problems. Try and source a better saddle before setting off. You should be able to find the bike new for under £500 leaving you something spare for those panniers which I would buy cheap from ebay. Assume the panniers aren't waterproof and put all clothes inside bin bags or equivalent, Have fun.