In my both 2262, i used about 9 Siporax bags and eight box of Purigem ( on each 2262 - total of 18 Siporax and 16 Purigem ), to get a chemical layer on it.
I decided to go with harleys setup but replaced the substratepro with matrix. this supposed to be a budget tank but..... decided to go balls to the wall on filter, hence the cheaper biomedia. but from what I have read it is just as good as the pro, and I have not found a person who has bad things to say about it.
Good call on the filter. It's the heart and lungs of your tank. I am always amazed how people buy expensive fish but go cheap on life support systems. Really, you should be very proud of a serious set-up, definitely a good decision.