If you want an S series engine put S14 in. Early 320is race cars had them in 92 and briefly into 93. But I'm with the others. I hope you have some very deep pockets for what you are suggesting.
If your thinking of spending that much money I do suggest a better investment in say a limited production car...aka E30 M3 or a E28 M5 or an E34 M5.
