Well, I just planted my tank and only saw one snail and snagged it out of there. I got mine from aquariumplants.com and am 110% satisfied. They arrived in awesome condition. Take a look at my albums. Those plants were planted on Friday, April 24th, yep like 6 days ago.
Get a couple clown loaches or zebra loaches to deal with the snails. From what I understand, they will make short work of them in no time flat. Can't help you on what to plant in sand, but I would think that if you fertilize properly, you could grow most anything. I am trying out aquariumplants.com's fertilizer pellets on my plants for six months. They guarantee them to be better than liquid and/or powdered ferts as the feed the root. They are not supposed to contribute to the algae. Like I said, they guarantee them to work or your money back. For $11 for 75 pellets and one pellet every 3x3 area or so and only once per month, I figured what the heck. It works out to about $5 per month in ferts and less headache with daily dosing, overdosing, how much to dose, etc. Set it and forget it, that's my motto (well, me and Ron Popeil).
They are a little more pricey than dry ferts to be sure but if it cuts down on algae (and headaches), I am all for it. I will report back in a few months, but check out my growth after just 6 days. I am impressed....
What is in those tabs? I would wager that they are not providing all the macros and traces you need, and that you will eventually bottom out on 1 or more... but I could be wrong. A lot of the plants you have are going to suck up the nutrients, especially with CO2 and the great lighting you have.