Hi dave, welcome here.
I learned deutsch for 7 years but I already forgot all I had learn...
I'm going about 2 or 3 times a year to the ring, last year it was with my saxo, and this year it'll be with my megane.
eventually, do you have a BTG lap time recorded ?
the "boitier" (ECU) you are searching for, is quite not usefull if your engine is stock.
It'll just get you more revs, but no more HP, and maybe less than you have without... (a french magazine did the test on a dyno and lost power with the peugeot cup ECU)
you should start with peugeot sport (or equivalent) intake manifold, a 4/2/1 (or 3Y) exhaust manifold, camshafts, and then think about de ECU
have fun here, maybe we'll meet each other on the ring