I also live in Naperville and am looking for furnace. You may try to get the estimation via Trane & Home Depot promotion that they are currently running (I saw Trane's booth at the Home Depot at rd 59 & 75th intersection). They have a couple of nice rebates going till April 15th... The guy who came in for estimation was from ARS and I was able to negotiate a 15% off the quoted price... I'm still not decided yet though.