The onyl way to compare these lights is by par. You have have the same par value then look and see how much of each type of light your running. If it takes 12 T5HO's to get the same par as a 250W halide then so be it. Yes you could OD the bulbs but then they only last 6 or 8 months.
There are a couple guys in lethbridge keeping SPS under LED's with good results. Good enough that I would try them with a DIY set up. Here is what they were using these though
http://cgi.ebay.com/LED-Aquarium-Lig...d=p3286.c0.m14