Due to the height restrictions of your grow space, I would not advise using a LED panel that uses 3W diodes, it will simply be too intense for your plants.
A LED panel containing 1W diodes is what you need, and the best ones of those are made by ProSource (
http://www.prosourceworldwide.com).
I own 6 of their 180W Illuminators, they are extremely reliable, and extremely effective.
You can keep a 1W LED panel as close as 6"-8" away from you plant (during flower) without bleaching or otherwise damaging the plant.
You'd have to keep a 3W LED panel at least 16" away from your plant during flowering to avoid damage.
The 180W Illuminators are on sale for $500 until Sept. 10th ($100 off the regular price).
I know it's more money than what you mentioned above, but they're totally worth it.
Not too mention they have a 3 year warranty and a 90 day money back guarantee.
If you grow a single plant under this light, giving it 3-4 weeks veg time, you will get results that look like you used,
at least, a 400W HPS.
I'm not joking, and here are some pics to back it up.
Pineapple Express, Week 8 (of 10)
Sour Cream, Week 8 (of 12)
If you are interested in their lights, let me know, and I can tell you how to get free shipping.