I would think Mike would know best, out of the conversations you had.
I mean, we all know they have put S/C'ers on the S54 engine already, but the only issue would be ( if I were to guess) fitment of the intake behind the driver side headlite, and probaly the heat exchanger design and fitment in the nose, and possibly the oil reservoir.
SO I would guess, the guy that said they have PLENTY out there already, is NOT taking into account the differences of fitment in the ROADSTER , as compared to the M coupe body.
And Mike probaly is... because the kits would have to be different for fitment of some items, but obviously not the Rotrex and bracketry for it.
I am sure you could MAKE the kit fit, but perhaps they have NOT designed tubing and fitment EXACTLY for your application, as a package.
But again, that is my guess. 
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1997 M3 coupe technoviolet 36K miles
RMS Stage 2+,10.5 lb boost,M50 intake, AA custom tuned, 46 lb injectors, 3.5 Porsche HFM, Aquamist,RMS headers, track pipe, B&B triflo, 4 wheel Brembos, Sparco EVO 2's, GC coilover suspension, 18 inch Schnitzer Type 3's, 225-40-18 frt. 235-40-18 rears, 3.64 gears, PWR 58mm radiator etc..
430 RWHP 331 RWT 05-22-06 75 degree day |