ORIGINAL: jmj

I have several engines to be converted;
3 Toro 25 double barrel
1 Toro 25 single barrel
1 Weedeater 21cc
1 Stihl 40CC

I want to replace the carburettors on all engines, i dont want to mess with rebuild kits.I want all the 25cc and the 21cc to use the same type of carb.
I guess the 40cc will need a bigger carb.

I do not know much of carburettor models and numbers, so i want some input of what carbs i can use.
It should be a well known type that is easy to set up, and with 2 needles.

Thanks.