apply in district office

USCIS (INS) DISTRICT OFFICES check the office nearest you. Not one of the 4 centers. usually 1->2 year. Sent I130 and I-485 together. Depend on which state and even which city you live. For example, there are 5 District Offices in Texas. Small state usually have 1->2 offices.
http://www.shusterman.com/aos.html