I am starting to prepare for my M16 getting out of jail within the next few months.

Whats the latest on 22lr conversions?

I've seen belt fed's talked about, but it seems like they are hard to get and mostly on the used market, right? Some also have more issues than others?

So then is CMMG the best option outside of that?

I was planning on getting the cmmg SS bravo conversion kit. Then I believe I need the auto sear trip kit as well from them? Is that all it takes to get it working? I noticed some people mentioning adding weights somewhere, but I don't see that for sale anywhere.

I was going to run this in an ar15 upper that I don't use often. Would it be more reliable to get one of CMMG's prebuilt uppers? I believe they already come with a conversion BCG and everything else needed. I'm guessing the only subsonic one (to use suppressed) is the 4.5" one, but I read that may not be too reliable.

Any advice or guidance would be appreciated!

EDIT: Founds something like THIS.. Is it needed to make things run smoothly in FA or should I first wait and see how it runs and then see if this is even needed?

I'm still using a CMMG sear trip that I bought to go with my first CMMG conversion in 2010.  In 2018 added 4.5" bbl. and 9" bbl. CMMG dedicated bolt/barrel assemblies. I have not had any breakage of a sear trip or an ABW with probably over 8K of rounds.  And for the last seven months I've mostly used my own D.I.Y., $0.80 each ABWs except for a few times that I used the CMMG and JAC ABWs as comparisons for ROF tests; so I don't ever expect to break an ABW.

Disclaimer:  I have no affiliation with or financial interest in any vendor or manufacturer; and I am not a competitive shooter or a blogger who receives any form of compensation for endorsements or favorable public or private comments.  Use of vendor and/or product brand names, if any, is for informational purposes only.

Best of luck.
MHO, YMMV, etc.  Be well.