The short answer is yes, you can use a Rubicon locker (front or rear) in a Mojave front. You'll need Rubicon axle shafts as they are a different length than your Mojave. Then you have to figure out wiring.
I'd just go ARB with your existing shafts.
Pattern isn't a concern but backlash is. Before you do anything to the diff, measure the backlash. When you reassemble with the Air Locker, make sure you match that backlash. If you don't, you'll very likely have howling gears.
You'll also want to make sure you have good preload. .010" from...
I haven't found any Truetrac style options for the JL/JT with the exception of the 30 front in the std JL front. I've always loved Truetracs and they could be a great option in a less than hard core built JT. Eaton hasn't shown any interest in JL lockers so I'm guessing that Truetracs won't...
I wouldn't do a Rubi due to the 4-1 t case. The 8 speed has a 4-1 first gear so a 4-1 t-case isn't needed anymore. In all but the most extreme rock crawling, I hated the Rubicon 4-1 case in the JK. It's too dang low and I found myself using high range more than I wanted. The 8 speed makes a...
What I have been thinking about is whether to choose the Max tow over the Rubicon. I've never been a fan of the Rubicon 4-1 t-case as many times it has been too low. Now throw in the 8 speed trans with a 4-1 first gear and the Rubi t-case is REALLY low. Get a Sport Max tow and throw in air...