i live in southampton and there is southampton reptile centre on spring road - the guy is really helpful and chatty and full of good advice plus you certainly dont feel pressured into buying anything! the other one i know of is grange reptiles on botley road (shares a plot with a garden centre) they seem pretty good as well and is where i got all my set up from! they hold reptile nights up there too which i haven't been to yet as ive only recently become a reptile owner myself but i am certainly gonna go to the next one which i believe is this tuesday (21st)! i hear there is going to be a nice bbq ect (as if that isnt enough to temp you!!!!)!
as for the portsmouth area there is southcoast exotics at waterlooville, haven't really had much dealings with them so dont know what they are like but the manageress seems helpful enough when i spoke to her over the telephone!
The online vivarium store is at hayling island - again not many dealings with them but seem to have a good range of stock for set ups
southern aquatics 1 in poole and 1 in cadnam(near soton) has a huuuuge amount of kit at relatively low prices, plus the staff in there have always been really friendly- never really asked advice on reptiles though so not sure what their knowledge is like in that area!!!!
wow sorry for the essay lol!