I have the PM1236T, I'm not sure what the PEP means so I'll pretend I know what I'm talking about
, If you have the room and budget for the 36"- do it. You'll get: more weight and a bit more stability, have that much more space for attachments like bigger chucks, drill chucks, long drill bits- etc, threading/tapping tools, the tail stock can be moved out of the way that much more. The larger lathe will have better resale value when your kids sell it.
Remember, the attachments that come with the machine are for getting you going faster and can be upgraded if you want. It's harder to upgrade the lathe features. -Yes, I'm happy with it, but to be honest I do far more work on the Mill.