Not what brand (getting RRA), but what kind?  I don't know what barrel length, or A1 or A2.  I don't want A3 (just sold).  This is just a general purpose rifle (target shooting, plinking, maybe hunting), I will put a cheap 3x20 scope on it (one of the $40 ones).  I am leaning towards the 16" (as I had this, and liked the balance/length), but what are the advantages of the 20"?  Are the A2 sights really necessary?

THanks,
James