I'm not even sure what you're aiming for, but if perhaps the word "transparent" could be used to describe what you're wanting, then perhaps the Dan-O Transparent Overdrive V2 would be a good option. there are some internal trim pots to mess with so it doesn't really "boost" your tone, I guess...
Katana Boost. Set anywhere from 0 - 3 or 4 it will get you sub unity. So engaged, it will lower your volume by quite some measure set anywhere from 1 to 3. Great pedal IMO.