You can have the relief valve altered to change the pressure if required. I've done a couple of mix and match power steering setups, and so far I haven't had to have any altered.
They have all been pumps that came out of rack and pinion cars and fitted to worm and recirc ball boxes.
The latest one, V6 commodore into toyota hilux, the steering is slightly heavier than my apprentices standard diesel hilux. My 94 mustang pump into MQ patrol feels about the same wieght as original.
I actually like the idea of the electric pump, no screwing about pulleys and brackets, and if your engine stops you would still have power steering to aid you in rolling off the road.
I've been looking at electric brake boosters also, Range Rovers use these, so could be interesting for my XL ute where this no space for a booster.
Cheers
Jas