A lot of the adjustable shelving options will be similar to the one you have used in the past. ELFA is by far the best choice in adjustable shelving, but if you feel that you are having issues accessing stuff on top, a sturdier system might only need two support arms as opposed to three, especially if you are just storing linens on it (nothing heavy).
Would you consider a different depth of those top shelves? For example, 16" depth is the standard, but many systems have 12" options. I find that using 12" as you go higher increases accessibility, but you can still utilize the space. Your storing options would depend on exactly what you are putting there. Could you share more information on that?