I was looking at RiverSide flight centre for my PPL training, as i aint made of money
I have no idea who or where RiverSide flight centre is, but i'm guessing from the price it isn't in the UK? Whoever they are, if they have a suitable aeroplane then I'm sure they can teach you aerobatics. However, you do need to consider what happens when you get back home, because aerobatics is an even more expensive hobby than flying in general - aircraft hire is more expensive, and you'll need to fly fairly frequently to keep in practice - so it isn't an easy thing to do on a tight budget.
(edit: ah, in the time taken to type that FNG posted and you answered my first question. I think the rest still applies though)
As an aside, if money is tight then I strongly recommend investigating the
PFA - once you have a PPL you can fly interesting aeroplanes remarkably cheaply, even in this country.