1) The CAA website has a list of AMEs
here. You should be able to find the other details you need there also.
If you don't need the Class 1, why pay for it? Class 2 is in the region of £100, + a bit for ECG if required.
2) You should be able to take all the theory tests at your flying school - except possibly the RT practical. Many (most?) FTCs don't charge for the tests - again, except possibly the RT practical. Check all this with the FTC - and use it is a basis for selecting one, if applicable.
You can study for all of the tests including R/T on your own. I found it very helpful to do a course in R/T, some others have found it helpful to do courses in some or all of the subjects.
Buy a few of the books - e.g. Thom / Pratt and see if you think you can learn the stuff on your own.
You will probably find that a lot of the stuff seems very hard to get your head around until you actually start flying - then it becomes trivial (well, nearly). Nav, aircraft systems, R/T are all much, much easier after practical experience, I suggest.
SD