Their was some cutting on my kit (RE5.5LA) but that was only the stock control arm brackets on the frame. Im not sure, but I think you might be able to leave those on, just bend them out of the way a little bit. But I remember those being pretty hard to cut off, and I was using a plasma cutter, also, the welding is not "required" just for extra strength, the bolts themselves are plenty strong enough as it is.
Oh yea, its about 27", from the ground to the bottom of the rocker.