ERPPC and AC10 both have 950 ft/s velocity, The 2D2 and the 2D both have an energy hardpoint on the same side as the ballistic torso, making these two mechs the best choice for very close weapon convergence. 3 jump jets feel okay, still not like pop-tarting used to be on the Shadowhawk, but pretty close. You might be able to get away with 2, but it doesn't feel like enough imo. You can also drop 1 DHS and 1 JJ for an XL300 version. (DHS located outside the engine for crit padding)
Played this last night in a 10-man. Was able to get 400-500 damage per game. Quickly steam-rolling enemy teams didn't give me much experience with a prolonged fight. The arm mount is deceivingly low and I was hitting hills for a while. I would not run less than three jump jets. Three is barely enough to achieve a proper pop-tart shot, but it is still doable. Will report back after more experience in the build.
I feel this concept could work on the Blackjack if you are willing to make sacrifices. Perhaps a 225XL, fewer heatsinks, half ammo and reduced armor on the unused arm. Such a build would have a better weapon mount and convergence. Maybe switch to a regular PPC. (On Edit) You might consider a TAG for shot clearance verification.
I run this build almost exactly, except I skimp on the heatstinks to make room for a XL295 (borrowed from my firestarters) and run a regular PPC with a cooldown module for quicker shots and less heat. It's great, like a mini Dragon slayer that doesn't take up an assault slot. I recommend running the AC10 range module to reduce the arcing, meaning you get more pinpointed shots. 5 stars from me.