I use a P8 with bells and whistles on it - can't fault it. I don't have launch control on it though - but you can get that from Motorsport Developments for any L1/6/8/P8 ecu now, they would probably do a deal if you bought a Live mapping session and Launch Control/ALS/Wasted spark for a L8/P8 in one hit?

Or you could speak to whoever is going to be mapping it - they might be able to suggest something that suits you, your budget and them.