Basically the 1.6s and sh have more in common with the 1.8 and 2.0 engines rather than the smaller 1.2 - 1.4 etc engines. There's normally plenty of spares knocking around, so you shouldn't have any problems there. As for goodies a 4 branch from a early 1.8 will fit a 1.6s/sh. You can also get a weber 32/34 dmtl to replace the varajet 2 carb. I've got one on my cav, and had one before on a small block 1.6, they seem to make a difference. Twin Weber's or bike carb's sounds like a plan though