Appleinsider(dot)com has a good buying matrix listing current best deals (including Apple Support, if you want it). In general, B&H Photo provides fantastic and professional service and support, with no tax unless you ship within NY.

...but, also, as Sailing mentioned, try Delta's coporate rate thru Delta Perks, it's often about 6%-ish off list price, which is a deal in Apple-land. I don't believe you get an additional discount on top of the Delta discount, just the refurb deal, which is great

Also look at the bottom of the Delta-Apple site for refurbished section, Apple usually has excellent deals on equipment a generation, or two (or three) older, fully refurbished, full-up warrantee. Kinda like buying a Certified Pre-Owned car, but better, since it's been remanufactured with full fresh battery, etc.