With that stash, I dont think you could go far wrong with KJMs house blend - (check out the 4 pages of well deserved praise!). I am currently sipping a flat white made with Peru, Mexican, Ethiopian gambella and Sumatran and at 7 days post roast its sensational (the only modification is swapping the central American - Guatemala -> mexican). To my somewhat barbaric palate I think the Mexican might add a little more chocolateyness.
The other blend I used to make regularly (before I discovered KJMs) is brazil 40% columbian 40% Sumatra 20%.
There you go, that should cover it nicely, let us know how it works out