I use a Lewin trammel base. Infintely adjustable for a 4" to 24" radius. Mid $30 dollar range.
http://home.earthlink.net/~customwood/t ... mpass.htmlRouter of choice is a Porter Cable 690 from my old woodworking days. While more expensive, I've been able to get extra bits and pieces when I need them. The only issues were a stripped lock bolt and a bad switch.
I was fortunate to pick up a PC dust collecting base years ago. Works on regular and plunge bases, and did a fine job of containing the dust.
I recommend getting a round clear base for any route one chooses.
Round so it cuts the same no matter it's orientation to the fence.
Clear so you can see the marks on the track surface.
Just my $0.02 worth....