Differences can include LED options, original price, case, layout options, color, quality, weight...
Should I keep going?
Kustom TKLs are really deep. The only names that everyone (should) know are: 356CL (and the 356 mini), Duck saver boards, GON's boards, KMAC 1.2 and 2, and LZ-S,SE, and GH.
The price differences are also related to the original price. KMAC 2 kits are ~$450 new, while 356CL DGE kits were north of $600 IIRC. A 356DE wouldn't go for over 700, since the kit isn't as valued as the CL.
The 356CL is pretty much universally regarded as the best. You'll get that opinion from here, both the major Korean forums (OTD and KBDlab), some of the Chinese forums, and pretty much everywhere else.