In Reference to concrete slab and floating floor

I am building a home studio in my garage in Orlando, Fl It's on a concrete slab 4 inches lower than the rest of the house. In the attached picture. the purple is the concrete block and the red is where there will be new wall studs, except the back wall opposite the garage door, it is already insulated and has 5/8" drywall, and that door leads into the laundry room. This is what I have so far... For the secondary walls i used pressure treated wood on the floor but between that i used a double layer of this foam owens corning sells to place between the concrete block sill plate link below... http://www.owenscorning.com/...n/produc ... msealr.pdf Now i have read some articles after i had put up the walls about floating floors ,but also the one about having a concrete slab. My question is can i make scores in the slab around the perimeter of the room and fill it in with backer rod and foam, then use a laminate flooring with a foam vapor barrier and not have too much vibrations. what is anyone opinion about using the foam stuff instead of rubber under the wood before i attach it to the floor. also above me is an attic ,the sheetrock is already on the ceiling and i really dont want to take it down, should i add another layer of sheet rock? I can go in the attic and put insulation if need be. THanks in Advance for anyones help Jason

Here is a link that works that shows you what the product looks like http://www.acehardwareoutlet.com/(4kedh ... 45ennusgqz)/productDetails.aspx?SKU=5401641

I just realized you have to copy and paste the whole link when you click on it it send you to the home page