The only time I recommend TBI heads is when someone wants brute low end torque and is not concerned about upper RPM. The TBI heads fall flat on there face by 4000 RPM, but they do provide outstanding low end pulling power. going with Vortec heads will require a Vortec intake which costs more coin. TBI heads also have different bolt angles at the center 4 which means you have to drill your intake or get a aftermarket one that fits them. Being the aftermarket intake costs more I can`t think of anyone who would waste there money buying one for TBI heads.
The cam you have is the same specs as the edelbrock performer plus cam. If torque is all your looking for and don`t plan to rev it as you mentioned I would go with the TBI heads. If the TBI heads need a complete overhaul, then you may as well buy new Vortecs and get a Vortec intake as well.
I wouldn`t use shorty headers or exhaust manifolds, I`d find some long tube headers. The Vortec heads are about 35 horses over the TBI heads.