Any one of those will support the cylinder fine. I am very partial to Mikuni and would steer you to the VM18. I also recall seeing more information regarding successful builds that give setup info using Mikuni, and more issues with tuning and phantom problems (that may or may not be the carb) have a PHBG. Seems that thing can just mystify people. I may possibly be noticing it that way due to my tendancy to focus more on things I favor but that is just my observation.
If it were easier to get a hold of a 12mm stock carb I would tell you to do that. It won't cost too much, would do just fine until you can drop a wad of money on better parts and there is a compendium of knowledge about builds using it. But, because that is going to involve buying a used part you can not always guarantee availability.