I've had my Clio 2 years in April and supercharged since last May. Definitely consider supercharging, also consider what you're going to use the car for. It's not all about pub bhp figures in my opinion it's about real everyday driveability and living with someone that's modified everyday.
If and when you choose to go forced induction the biggest decision is ECU, my 2 pence and based on personal experience.... Go aftermarket, you think you'll save money mapping the stock ECU but what you lose out on is the potential to read and tweak the map anytime you see fit. For instance on my Adaptronic I can have a map e mailed to me from EFI Parts and load it up straight to the ECU, I then have the choice to flip between the 2 maps so say one for trackdays running slightly less power but good for constant wide open throttle then back to the original map. You probably know all this but the bigger picture is aftermarket pays dividends in the long run, there aren't many people that can map the stock ECU
What personally works for me going supercharged opposed to turbo:
You don't touch anything exhaust side, so no need for a turbo manifold, turbo link pipe, downpipe , turbo. Think of all those joins, all those nuts that could come loose (and more than once) and how hard it is to reach some of them tucked away down the back of the engine near the bottom.
Supercharger power is progressive, smooth, and couple with the F4R which likes to rev, the charger will keep on going. There's also no torque spikes when coming on boost like turbos so it's kinder to the gearbox, although it could be mapped out to be more progressive.
I'm running 262bhp and 220 ft/lbs torque, to reiterate that's about 90 more bhp and 70 more ft/lbs torque than a stock 182, on the road and useable everyday with a stock Valeo clutch.
http://www.cliosport.net/threads/ricardos-petrol-blue-supercharged-182-project.734722/page-9
