I wouldn't go near the suspension that's for sure! In fact depending on the differences in weight between standard single piston calipers and 4 pots you could run the risk of upsetting the damping...perhaps only an issue if fitting bigger disks as well, keeping standard disks + new calipers would prob. be OK weight wise. There is no doubting that the standard items do feel a little wooden at times...lines/new pads could be a shout along with some new fluid. Renault disks and some DS2500's or the likes.
Why is an orbisound so good, other than it costs 2-3 times as much as other exhausts? I doubt it's going to bring huge power increases? I wonder why other manufacturers haven't 'copied' their single back box design, it'd prob. save a wee bit of weight? Does anyone know the weights of the standard exhaust vs. various aftermarket items?
Matched inlets seem like a good shout, sorting out a problem that shouldn't be there. I'd prob. be tempted to do that followed by the Morego 202 upgrades (although not necceserily bought from them) i.e exhaust, filter and remap...I wouldn't bother with the cams.
You've got to be careful when modifying a car like a Trophy. The reason it is so highly reveered is that in standard form it is brilliant...swapping the seats, changing the suspension (epic fail!), fitting 'better' tyres and a loud exhaust are really only going to ruin it! Renault Sport didn't spend 1000 of miles testing the car and making improvements when they could have nipped down to demon tweeks and slapped on some coilovers.
The idea of getting tutored track time is good, I've been driving my car since November, think I am reasonably competent behind the wheel and I am NO where near using everything that's available...haven't been to a track for a start.
Service then a uk/european driving holiday? Could be a shout....
Might be worth treating it to a professional detail as well, just to keep it looking it's best! Lots you can do with £2.5k