Agree with 'spdrmn', if its a dedicated track car (i.e. limited to no street use) then solid mounts are the way to go. However, I would NOT run solid motor mounts without motor plates (which will be custom). You do not want the stress/flex from the chassis and suspension to be taken into the block. It will cause your block to crack at some point in time.
No experience on #2
I have seen roll cage kits for the Z that I was considering purchasing, but they (obviously) require welding and minimal custom fitting for installation.
