Mikuni carbs on a road bike?

I've posted here before about my bantam cafe racer, which I got on the road 2 weeks ago. The engine is freeing up, so I'm starting to think about how to make it quicker.
So far it is a fairly standard D14 engine. As detailed elsewhere I have smoothed/matched the ports, had it bored to 185cc using a suzuki TS185 (I think) piston and T&G autos conrod kit on the crank. Porting is standard, carb is the standard amal 600 series and exhaust is the standard one I nicked off my D14.
My first question is regarding the squish band. I measured it using soft solder, and it came out at 60 thou. I read on here it wants to be 20-40 thou. Putting in a thinner head gasket would reduce this to 40 thou, and I did make one from copper foil. Despite annealing it, it leaked so much it wouldn't start. So, how can I get it to seal, or should I just grind the head and barrel in and remove the gasket completely?
Second, I've been given a chinese copy of a keihin carb to try out. (Sheng Wey PD5, apparently). It looks like the one fitted to CG125s etc. Can anyone advise on what jets/slides/magic beans would be a good starting point? Also, is there any advantage in making a longer inlet tract? I'll need to make an adaptor anyway.