I can and like to fabricate and mine is 2wd and will end up low, so I could care less if they bolt into the stock mounts or not. Plus even if it is working for guys to use the stock upper/lower shock mounts to bolt coilovers into, I still personally don't like it.
You can PM if you are willing to talk to me about it if you want. I don't want to clutter up your thread with my crap.
na its all good! if you cut out the upper shock mount, you can make any coilover work for your ride height. its when you want to keep those mounting points where it begins to become a pain.
What i would do is find where you want the suspension to stop on its full upward travel, take a measurement from teh ground to the hub. then let the suspension drop to where you want full downward travel to be and take that measurement from the hub to the ground. subtract the downward travel number from the upward travel number and thats your wheel travel. Divide it by two and thats essentially the shock stroke you need to make it work for your suspension. Now with that info, you can start searching shocks you want to use and using their extended and collapsed lengths, you can start finding what shock will work based on its shock stroke and lengths and where it needs the upper shock mount to be mounted. the biggest key is you DO NOT want the shock to be the limiter in any part of the suspension, specially if your going to build a new upper shock mount as its much easier to NOT have that happen. i have always used the rule of thumb of "keep a 1/4 of shock shaft showing at full bump, and 1/4" of shock shaft left to extend at full drop".
it sounds complicated but its really not. just lots of measuring, recording, searching, and back around again.