how long are the
5 port phantom FS
A2 FS
Votex FS

i heard vortex actully improves accuracy

Essentially, the Vortex design tends to improve accuracy -- however, that is not a function claimed by the factory.  My own experience with a AT LTD TTR-700 and COMPAK-16, both equipped with Vortex designs tends to support that observation.  Also, I've read reports from APG, MD on the M-249 tested with the Vortex that showed a dramatic increase in accuracy.  However, the test data pertained to the older G4/G5 designs.  I don't believe the Army has tested the G6A2 on the M249 as yet.  also, I've read reports of an M24 SWS modified by the Army and tested at JRTC with similarly impressive improvements over the bare barrel.  

so i should get a vortex instead of a a2

Vortex for a carbine, A2 for a rifle, its long enough already.

I have a vortex that the fingers are spreading outward. Some vague recollection that there
may have been a bad run, or maybe it's a cheap knockoff, or something. I have switched to
the phantom on my most used 16" upper.

Or you could just get a Phantom.