I swung by the Wet Spot the other day and picked up an ADA Mini-S for about $58. I've been looking for a decently priced light, and see you're using an archea from Aqua Forest. Would you recommend it? I e-mailed, not sure if they still sell it.
I'd say definitely try putting a sponger or mesh prefilter on your intake to protect shrimpies, and check your filter, I found about 6 babies happily hanging out in my filter when I didn't realize my prefilter had fallen off!
You may have to clean it quite frequently to keep the water flow up, but that's probably better than losing all of you shrimp right?