You may have to contact MileMarker directly.
By Phone: (800) 886-8647
By Email: info@milemarker.com or
sales@milemarker.com
By Mail:
Corporate Headquarters:
2121 Blount Road
Pompano Beach, FL 33069 U.S.A
I've dealt with these people myself and I got excellent support.
Here is MileMarker's web page for this part time kit:
CONVERSION KITS & ACCESSORIES
Yes, another option is to install another TCase but that's not going to be any easier. You will still need to install manual hubs in front. But the biggest catch to that plan is the rear axle. Your differential is off-set to the passenger side. Most TCase options would have a centered rear output (except the older Dana 18). That means you may also have to swap out the rear axle with one that has a centered diff (they are common) but then the gearing has to match.
I have seen a jeep that had a Tcase with a centered output and an axle that had an offset diff. The owner said he didn't have any problems but you still end up with much higher angles on the driveshafts than you should. It's not a recommended setup but it works (kinda).