Post some pics and we can tell you.Or do a search on each engine you have and there will be a thread devoted to that engine to convert it.
With part numbers and references in the most part.
As for carbs most of us use carbs in the 10mm range.
Im trying to open the websites addy i have for numbers but its not working right now.Just look at the individual threads and the best carbs should be listed in that thread for that particular engine.