Ball lock kegs usually work better for keezers(taller and skinnier). When I was putting my kegs in my refrigerator with cobra taps pin lock dimensions were better though.
Really good advice already in this thread. Get the biggest CO2 tank you can accommodate. Putting it on the outside will allow a 20 pounder. Will save tons of money in the long run.
EVABarrier and Duotight stuff works great, and not just for beer/gas lines. I use them for my jumpers now too.
One thing I had an issue with in my keezer was temperature differential between top and bottom of the keezer, which was causing foaming on the first pour. Even with 2 fans I was having issues. I think it was because when I had 4 kegs in there they were literally packed together as tight as possible, allowing virtually no airflow in the bottom half of the keezer. I ended up adding more fans and put one of the kegs on a can to raise it up and allow a bit more airflow at the bottom, alleviating the issue. Something to keep in mind if you ever have foaming issues, which is a common problem(although can be caused by many different things)