If you can find the German hammered aluminum reflector that is the best you can buy. No hot spots created with those. My personal favorite and the ones i use because of its small foot print in comparison to those giant pendants is the Lumen Max 2 which they dont make any more.
http://www.saltycritter.com/lighting/sunlight-supply/lumen-max-2-metal-halide-pendant-reflector.htm
+1, jackson6745 know the BEST reflectors, i got 3 Lumen Max 2, i just love it, i use to have one H.T. i give for free (NEW), far a way compare to Lumen 2, i pay $ 90 for one 250-400W ballast .
If, i was you, i will give up in T5, got some LED bar (Royal blue and purple), run Leds 2 hrs. b4 and after MH.