I'm using a multi keyway rollmaster with thurst bearing behind
from romac in Oz
www.romac.com.au
tiz nice and i've had no issues
gears make a racket that sounds good for the first 500 miles
and then is a pain in the ass
and you can transmit harmonics from crank to cam that have a detrimental effect on anything that runs off the cam. i.e in some engines the dissy and oil pump. if the dissy is gear driven rather than offset dog a Nylon gear can help mitigate (i don't know about anything other than my own which is gear driven)
you could go for gilmer belt drive just to be different
need special pulleys and water pump covers and a good bit of space
and a tensioner
Dave