Attic Storage

I am a new home owner of a brand new contractor grade spec colonial home and would like to install a small storage area in the attic or maybe even a walkway down the middle for future air handler installation.  The problem is in addition of having the standard pink insulation in between the joists, I also have about 16"-20" (not exactly sure) of blown in white insulation.  One white layer of snow......

I've researched everywhere and everyone seems to have a different opinion on how to go about doing this.  Elevated floor?  Just rake the white stuff aside and lay the plywood over the joists?  Please help!

I do already have the pull down stairs in one of the bedrooms to go up into the attic.

Thank you!