Depending on the weight of your ride, you might need a stall as high as 4000 rpm but at some point it will no longer be streetable. I would not go to 5000 rpm.

As for the holes in the butterflies, that is all you need to do. I would start off with one hole in each of the two front butterflies the size of 3/32 of an inch, for a total of 2 holes. This will allow for better air fuel mixture at idle. Let me know how it goes.