Mondello makes burrs specifically for porting and give really nice finishes.
I know it tempting to go for the cheap ebay type stuff but don't do it. Burrs like that usually have all sorts of issues like balance, too aggressive, poor finishes and worst of all...the long shaft burrs can fly apart, which is bloody dangerous!!
Get some quality short/long burrs and they will last most people for years.

______________________________________
IF YOUR USING OTHER PEOPLES IDEAS YOU ARE ALWAYS GOING TO RUN 2nd.......