I will give this a big X2Instead of looking for a new cheap model, I would look for a used premium model. (and not the new Premium line they have). What I mean is I bought a RG321MH for 300USD a few months back and then a month later I saw a local guy selling 91 or 92 RG570 for 300USD. The 570 would have been a professional quality instrument compared to my 321.
That being said, I can give you advice. I would completely stay away from the GIO line. (any guitar that has a G in front of it. GRGR121EX) The RG3xx series are generally regarded as good, as long as you don't have the EDGE III tremolo on it. The new ones have an EDGE-ZERO which seems pretty good.
I don't know anything about the Cort, although they used to make guitars for Ibanez.
All those other guitars would be a great starting point. For a fat metal tone I would look for something with a Mahogany body, but it doesn't have to be.
Would you rather have a brand new Kia, or a used Corvette?