Like the guys said, no maf needed. Keep your stock one, a larger one won't add any HP at this point, and the stock one will keep your a/f more accurate. If you had a 4.2 with H/C/I then i would say go to an 80mm GT maf, but you're not at that point yet.
SCT is a compnay that supplies custom tuning hardware and software to its dealers www.sctflash.com
I am one of their dealers.