I dont feel you need that airpump.
I would double the depth of your sand bed. You dont need to use live sand the second time around as any sand will quicklyi become live from your existing sand. Add the new sand slowly to build it up.
Add a few more lbs of LR
and then you can slowly start to dump those bioballs. Your live rock and sand will have 1
the filtering capacity of those bioballs.
On a side note look at that RIO pump very carefully as the 2100 has a bad trackrecord for breaking impeller shafts or simply not starting back up after its been powered down.