I don't know what area you live in but there's a course in Birmingham. If you can't get there they do a correspondance course and you can start at any time of the year. It does cost but not too much. I'm actually doing the foundation course myself. Nearly finished it though. Here's the website Reptile rehoming, reptile charity, gifts for reptile lovers
Hope that helps you mate.
Let me know how you get on
Depending on what kind of qualification you want I know Bangor University offers a herpetology module in the third year of studying zoology and conservation and the person who teaches it is a very good herpetologist with lots of published works (some i've tried to read myself but they're a bit above my level).
I'm thinking of doing the Proteus course (mentioned above) myself so if I do it before you or find anyone who has done it i'll give you an overview, but the description on the site sounds as though the course is worth the money.