I have been pursuing almost exactly the same idea for a week or two now - I am much more restricted in possibilities by the 2.5" maximum legal blade limit in my town . . . . which means I need a wide blade to produce the most cutting edge possible for short length. With 3.5" to work with there are many options, but you're talking about something pretty bulky for the pocket, especially when shifting positions, sitting/standing, it might get uncomfortable. Makers who offer nice FB knives of the smaller sort would be Dozier, Nealy, Kevin wilkins, Rob Simonich (I'm tending towards a scaled-down talonite Cetan at this point myself), RJ Martin (his Handyman gets good reviews), Fred Perrin makes some neat small knoves with derringer handles, and . . . oh no . . I forget his name, go back 20-30 days and look for neck knife threads . . . he has nice small tantos in great-looking multi-carry kydex sheaths for something like $80, really can't beat the price. Lotta options, choosing among them is the hardest part.
Sheath - I'm trying to devise a kydex rig design that has a clip that attaches to the pocket, like most folding knives, but sinks way low into the pocket, so that the knife is inside the pocket but the sheath remains clipped in place on the draw. Problem is, with a long knife, when you sit you're likely to push the whole package out of your pocket. Still working on this . . . .