Hi Gareth,
the other guys have great advice and know lots more than me,but from expierience if you know what you want as the finished article work out what you can afford to spend( be honest with yourself,but not SWMBO
) and
work backwards.If you want a car in showroom condition that is great but what spec do you want engine,suspension,paint etc. as per factory or subtle upgrades,because unless the car you buy is exactly what you want to start with an engine upgrade could end up costing nearly as much as a rebuild(or more),suspension can make your wallet light very quickly,and re-painting a good but not to tatty body could cost as much as a very tatty body.ie if you are going to change most things look for solid base to work from.
Plus 2s cost the same and sometimes more than 2 seater elans,especially if chrome and trim is missing to restore,but as the others said do as much research as you can. Cars do come up for sale on this great forum,which has the the advantage others may know about it and may even have a bit of history on the forum,mine did which i have found useful.
Just remember to walk away if you have ANY doubts there is allways another car to buy,decide in haste repent at leisure(ask me how i know
) good luck
ps i am in Brighton you can ring anytime.I have just started resto (pm sent)
regards
Paul