Polar fleece is a lot more readily available than antron, that's for sure, but even it can be hard to come by... your best bet is checking actual fabric shops, as opposed to general craft stores that also have a fabric department.
If they have the color you're looking for, then that'll be your lucky break.
I can highly recommend polar fleece, it's really fuzzy, and it does a very decent job at hiding the seams, more so than standard polyester fleece; I used it for one of my puppets, and using the Henson Stitch method for the head construction, I was thrilled with the results.