You don't want to use sil for a quilt, especially a top quilt. You want breathable nylon for the shell. If you use a non-breathable material, you're going to get a lot of insensible perspiration (you'll wake up wet).
And while Thru-Hiker is wonderful for the latest and greatest technical fabrics to save weight, they're not so great on their pricing for things that you can get elsewhere. APEX 5.0 is going to be about the same cost there as elsewhere, but you can get breathable 1.1 oz/sq yd seconds (cosmetic defect, not a structural one) from DIY Gear Supply for $3.20 a running yard. Minus shipping, thread, cord, and cordlock, that drops your cost for the project to ~$64. If you insist on the most expensive 1.1 nylon DIY Gear Supply has, that raises the cost to ~$73 before all of the rest of it.
Hope it helps!
Bookmarks