well, i think 20# of rock is too much in a ten gallon, but i suppose it depends on the density of the rock.
I implore you to use all live rock, especially on a tank this size...it may cost you $70 or so to get all the rock, but that will be almost all of the expenses for setup (other items you will need is a salt mix and a hydrometer). Besides, the LR will kick off the cycle in your tank if it is uncured, and if it is cured you will not have a cycle at all...I understand that you are on a budget, I think we all are, but waiting another month or so and saving up some money to buy the proper stuff is in your best interest. Doing SW on the cheap is hard, not impossible, but hard...and starting off without LR is a step down the wrong path IMO
you can use your aquaclear for waterflow but run it without the filter media