Built myself a Stabber to try this out. Hit 3073 m/s with 2x istab I, 1x nano I, Cruiser IV, Nav IV, Acceleration Control III, and a MWD I. Hitting 3.5km/s shouldn't require more than ~2 weeks of training for me and a named MWD.
With a LiF Fueled Booster, I got up to 2 km/s with 3x istab. It accelerates slowly. I want to make it work, but I just don't know. Myabe with crazy -mass rigs or something. I'm not sure if the -mass on the istab affects the AB +mass attribute.
With a 10MN AB I, it's just 900 m/s with 3x istab. I think the 900m/s AB Stabber would be a pain to hit with turrets, but drones and missiles would pwn it.
I'm thinking, though, that it really needs a pair of heavy assault launchers and extra speed rigs instead of max falloff rigs. What I wouldn't give for another missile hardpoint, or like +15 drone capacity.
Dang 0ML 1 run Hurricane BPC goes for 5M. Researchy researchers, get researching already!