Rich, I'd say suspension and brakes would be a must-have if you put the Aero power to over 400bhp!
I think a
road sports based Aero could take the increase on standard units.. (+ possibly the anti-roll bar) more importantly a decent pad material and tyre combo would be more appropriate.
As for the suspension.. I suspect these will be Ohlins with Bilstein springs so you're probably looking at £3-4k for the kit + fitting (which AFAIK requires engine removal for the fronts) so would have thought total bill inc. fitting will be in the ball park of £4-5k depending on kit price.
I had Ohlins fitted to my Cerb and they really transform the handling, but a lot of Cerb guys are running well over 400bhp on units equivalent to the stock Aero units..... I would get the most from what you have before you start strapping £5k's worth of suspension to the car.... obviously for track stars... this would be a good investment due to a higher duty cycle...
