If you're in commuting distance of Brooksby Melton I'd see if Ingestre has any Stage 4 exams coming up. I've known people travel from Sussex to Ingestre for their four...
I did my stage two there. Nice place and friendly staff. I havent seen the xc so cant comment on that. For the two they were nice enough horses. I am pretty sure they do training there so could be worth popping along to one of the sessions as teapot says and see what it is like? It was probably about five years ago when I did my exam.
Unfortunately the Ingestre Stage 4 is on a date I can't do, otherwise I would go there (having spent two weeks over the summer with them!). Likewise unfortunately wouldn't be able to get up to BM until the exam day. Going in blind, what could possibly go wrong?!