Hello Eric & Jill,
The most comfortable topper is natural Talalay Latex. 2" of it is all you'll need.
Latex is, also, the longest lasting of all the different types available.
Not only will the latex topper provide the surface softness you want, it will also retard the wear of the mattress...causing it to last a lot longer than the manufacturer intended.
The 2" Soft Talalay is the one that gets all the rave reviews...and the one we use at home.
Either the EverEden or Pure Bliss brands will do nicely...shown here:
Factory Direct to You....
All Items Made Factory Fresh to Fill Your Order
Free Delivery Nationwide....NO SALES TAX.