When I'm targeting smallmouth, I usually use a Clouser tied on a #10 Mustad
bass bug hook. I use the same hooks to tie dear hair poppers, but usually
go sub-surface for smallmouth. The biggest smallmouth I catch are in the
16" range, and I've never seen anything a whole lot bigger caught in this
part of Pennsylvania.
This LMB took a #10 Wooly Bugger, and was caught on a 9' 5wt Z-Axis:
I caught a 22-24" channel cat in March, on a #12 Green Weenie and an 8'6" 4wt:
The channel cat made several runs, and was a real hoot. The LMB just played
tug of war, with shorter runs. You can see the little Green Weenie in the
cat's mouth BTW.
With a proper leader and an oval cast, I can get a smallish deer hair bug
out 30 feet. I had never seen the cast until I watched Joan Wulff's video.
A 6wt makes things a whole lot easier, however, and if I were going for
bass, a 6wt would be the smallest rod I'd choose. After that, it's a matter
of how big your patterns are going to be.