I'm about half way through the AOPA basic aeros course flying in a Pitts S2C at Fairoaks. I can tell you that the S2C is a very nice aircraft to fly and having had a look at the Aerobatics Leicester website, the rates there are very reasonable. It looks like they also rent the aircraft to students which is something worth considering.
I've got to a point where I'm thinking about whether I can rent in future or if buying a share is the better option. My advice is think about why you want to do the course and what aircraft you want to fly afterwards. If you do the course on a Pitts, the rental options seem fairly limited but if you're thinking about buying a share or if you have a particular aircraft in mind it might be best to seek training on that aircraft from the start.
The course itself is pretty good. It covers loops, barrel rolls, aileron rolls, 3/4 clovers, wingovers, and all the other fun stuff that was taken out of the PPL syllabus long ago. It's the best flying I've done so far and I suspect it will be for you too!