Im no expert but i would of thought youd be better putting carbs on a valver.
1 because its a better engine to start with (que the arguments!)

2 because the intake manifold enters the front of the block rather than the back of the block like and 8v giving better induction.
I met a guy who had highly modded a 1.8 8v with a mechanical race head and twin carbs and we went out for a little race round a very quite quaint scottish road. I was astonished at the power this thing had. Mines a 2 litre 16 valver and he was still a little quicker than me! This engine was full race spec mind you! One thing i did notice which i was a little scared at was the fact that once the twin carbs are on they are so close to the bulk head that you cant even fit filters to them so you have to run without which isnt good!
Id recomend a valver with a 2 litre bottom end and twin carbs if you really wanna go the carb route.