What diameter do you have on now? I use a 1.5 inch roller coated with about 1/8th inch of JBWeld and sand making it about 1.75
You can order pegs on ebay and pick them up at any bike shop. The bigger the peg the more speed you get but also lose power. For me 1.75 inches was about right. I hit 22mph pretty easy and take hills around 15mph.
i reread the post and I get it now....
I'm not sure what else to use... pegs have always worked for me. Deacon uses a pipe cap and nipple from home depot. He welded a nut to the cap. But you could drill a hole slide the cap on , and double nut it in place and then screw the pipe nipple into the cap. Make sure you loctite everything in place...