Is the CV boot torn from a branch/rock/road debris, or from rubbing along the fins? If it's from rubbing, you'll probably see the other side develop the same issue soon enough, but if the hole is just from random debris I wouldn't worry about the other side. The replacement job is pretty simple, although you need a special tool to crimp the clamps if you use OEM style.
So you have an aftermarket coilover (Fox)? Is it taller than stock? I think you'd be disappointed to go back to OEM Bilsteins (mushy), but if you are going aftermarket Bilsteins that are better than OEM spec that sounds Ok. While you are in there changing the boot(s), you could pull the coilover and take it to a shop with a hydraulic spring compressor and have them swap out the struts. It's worth every penny of the ~ $60 per side.....
1976 FJ40 - green and mostly stock
1996 FZJ80 - not so stock