Rewired the power in my car and my computer now survives crank!
What I've got for wiring now is:
4 guage from battery going to one of these..
and then one 8 guage wiring going to my amp, and one 8 guage wire going to my 300 watt inverter. I've got another one of those distribution blocks for the ground now, with a short 4 guage wire going to the body and ground for the amp and inverter coming off of it. (will post pics later)
Connected up my computer to the inverter, plugged in my screen and turned everything on. I started playing some mp3s and then kept working on fixing some other things in the car.
After 2 hours of the computer, amp and screen running on battery power, I decided to start the car because I didn't want to kill my battery. The inverter has undervoltage protection in it but the amp has nothing so I still needed to make sure. I didn't even think about the computer surviving crank but it did! After running everything on battery power for 2 hours! I was really happy Just working on something to shut down the computer now.
Anyways I will post more info along with some pics once I get my screen mounted.