I am looking for sheets to fit on a pillow top mattress with a 2 inch memory foam pad?
The sheets I have now slide when I am sleeping and I have to pull the sides of them back under the mattress. Is there a certain brand that will fit and stay in place?
I would look for any brand that says "deep pocket" or "extra deep pocket" to help give the extra height you need. Measure the distance from your mattress to the top of your topper. Some of the packages will even say "fits up to 16" depth" so knowing how high you’ve got will help. Alternately- you can buy "sheet holders" that can go under your mattress and clip to the 2 corners that will keep them from sliding off! These are great, cost only a few bucks, and can be found at home stores (bedbathandbeyond), online and (MAYBE?) supercenters as well. Then you don’t have to buy new sheets!
The least expensive route would be to keep your existing sheets and used what are called http://www.stlbeds.com/articles/2009/08/06/sheet-straps/ sheet straps.
As far a what kind of sheet you will need to fit your custom designed mattress simply measure the total thickness and then shop for deep pocket sheets http://search.yahoo.com/bin/search?fr=ybr_sbc&p=Deep%20Pocket%20sheet%20sets that fit at least that measurement.