I use and 8' 4wt. I can catch the average 1-2# bass as well as all the gills and specks I want. A 4wt will cast everything but a big popper or hair bug. If you really want to have some fun, get a 1 or 2 wt and become surprised at what you can catch on those...

www.byrdultrafly.com for some info on the 1-2 wt fly fishing rods.