I switched from a 4x T5HO bulb to Radion Pro's on my 20g Tall tank which is mainly SPS, but I have a good amount of LPS (Acans, Chalices, and Lobos) too. I couldn't be happier with my decision, even though it cost me **** near a grand. I was looking at those cheaper LEDs or DIY but decided against them. The reason I decided against the cheap ones is they were either Blue, Royal Blue, and White, or if they had more colors - they didn't have a full control unit, no warranty, and were of questionable quality. Of course DIY is a great decision if you are even a little handy - but my problem was finding a NICE looking enclosure to hold all the LEDs so there are no wires hanging about - I didn't want a rats nest of wiring hanging from my ceiling.
For your budget - I would REALLY suggest taking a look at the new AI Hydras - they are $399 a pop, fully computer controllable, and FULL SPECTRUM - the same spectrum as my Radion Pros that were twice the price. Don't buy garbage - buy something nice if you are making the upgrade. The Maxspect Razors are also really nice and mostly full spectrum.
#1 Piece of Advice: Don't buy a unit you don't see in person. Make sure you like the way it looks and the way it grows coral. Look at the LFS - they will let you play around with the controller and settings. If you are spending $700 on something, don't buy some piece of crap off of ebay just to save a few dollars - LED lights are in investment. If you buy a cheap B/RB/W unit, you will probably end up switching back to T5s or go with MH - or It'll break...