from the horses mouth.. 720p 1080i is fine for cable/satellite feeds. Really only blue-ray picks up the 1080p.. 60hz on a 32" is great you won't notice any difference unless you go up in size. Since you have the custom made cabinetry he said pick it up.
He said warranty is your call, safe side pick it up. Workers do not earn commission on warranties at best buy.
on a side note, they price match. Someone good with computers could find, create a similiar advertisement from somewhere else save you some cash to lay on the Bears over the Seahawks =0)