I'm a wee bit late getting around to this thread, but I print up to 8"x10" in-house with an Epson R800. The archival qualities of the photographs are outstanding. It does require being able to calibrate the monitor, but if one intends to do professional work, one needs to learn how to calibrate one's equipment anyway. I've found Xrite Monaco calibration products to be top notch and very easy to use. I started with their Optix XR to calibrate my monitor and added EZ Color for my scanner (it also does the camera, printer, etc.). Yes, it does help to calibrate one's scanner.
For anything larger than an 8"x10" print I take it to a photo service in Fort Worth, TX. They've done some lovely, 16"x20" prints for me lately. We had some initial problems, but I soon learned how to work with them. Those problems were on my part - they ate the cost of my errors too which endeared them to me!
I would love to be able to get an Epson 4800 printer so that I could do my own 16x20's, but it's not economically feasible for me, just yet. I'm hoping that I can add that lovely beast this coming year...big drool, lol.