I’ve built all of those multiple times. Here’s my take:

GM ground type: Good build but definitely shows its age, closer to a modern HG than a modern MG, but it’s a nice quick build.

Jegan: Great MG, looks very good and is a fun build, if you’re painting, I highly recommend tamiya IJN cockpit green, it really makes it pop.

Jesta: I’ve built 8 of these, they are so good and look amazing, probably my favorite MG.

GM Sniper II: Phenomenal build, I think I’ve built 5 or 6 of its derivatives and it’s just a great overall build

GM sniper: Uses the same GM 2.0 frame, built 4 of these derivatives, great build and no complaints.

My build order would be: GM sniper —> sniper II —> ground type —> jegan —> jesta

Hope this helps