I can not see 37" and 4" as being LCG? 37 on a no lift sure maybe a 2.5 spring on 37" is a LCG kinda. No way you are going to get into a 4" inch on a 2d with out changing alot, to do it right, no matter what the dealer thinks they know.
Unless this is for "looks" then you can get cheep on 37"s. If this jeep is going too see REAL wheel time. This is going to be one very exepensive build if the dealer is doing it all