Lets try to figure out why your stock carb leaks.
The simple NT or Speed carb in my opinion is the easiest to tune.
Can you post a picture of which carb you have?
It could be that your float has sunk(doesn't float anymore) or the bowl gasket is broken or missing.
Your float may be out of adjustment with the 2 tangs that it pushes against to close the inlet needle, or the inlet needle won't seat because it may have something small lodged between the needle and seat.
These are simple carburetors.
My suggestion is to get to know your carb before you even begin to even think about tuning something more elaborate with several circuits that need to be tweeked, rejetted and doodled with.
We will be glad to walk you through it if you are willing to take the time and learn how to work on it.
TiM