Differences between FGC9 and all variants? Which is your favorite? Which is easiest?

Hi everyone, pretty new here and trying to determine what is different between all the FGC9 variants and would appreciate any summarys anyone can offer. I am having trouble separating them as there exist so many variations and remixes. So what I have put together from my own research is:

• FGC9 MK1 - original, possibly have option to use an airsoft FCG (i think).

• FGC9 MK2 - most recent FGC9, option for weld-less bolt.

• FGC9 STINGRAY - rifle length FGC9.

• NUTTY 9 - easier BCG assembly, all metric FGC9.

• PARTISAN 9 - not sure (maybe integrally suppressed?).

• URUTAU - bullpup FGC9.

• REBEL 9 - not sure (im assuming use for scorpion mags).

• ROGUE 9 - not sure.

• MOD 9 - upgraded/current version of the OG derwood AP9. i heard it is a bit more challenging technically.

• WTF 9 - not sure.

I am thrilled there are so many options but it is also a bit overwhelming when choosing.

Which is your favorite version to make? Which is the easiest to DIY with hardware store parts? also does any of them exist for 22lr? i think i remember seeing a MOD9 in 22 but i may be mistaken. Thanks for your help!