@farmerman,
Unless I missed it, you never specified if you need a combo printer. I'll assume that you don't want an all-in-one printers or a combo printer. I'll likewise steer you to an inkjet as most will render good-to-great color photos and do a decent job with text and/or in a combo in an image.
Most of the good color photo printers are somewhat costly to print - particularly if enlargement is needed; however, convenience and printing speed are also important.
Whether a printer can do mosaic printing seemlessly with invisible overlaps is dependent on a graphics program. Am I correct in saying that Pixma has a built-in capability? I'm pleading ignornace on that. I use graphics proggies like Photoshop or others that provide that function.
Some printers by pass the need for the computer as they don't need it as they've built-in interface panels and get commands to go straight from camera to printer. In that case buying a Canon Pixma would serve you best, but Epson can also do the task. You would to see them demoed to determine their convenience.
However, my preference is that I like tweaking the print using a graphics program so that functionality is useless to me.
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However, what matters most is the overall cost to own and keep in good repair. That is where it the rubber meets the road. The overall cost has to do with ink cost (as well as usage), dependability issues and prints not jamming and not neeeding endless cleaning cycles. Smaller printer mfrs companies are hard to locate ink cartridges a short while after the model has been out.
Personally, I'd not advise for a purchase of a Kodak printer 'cause as a corporation they're hanging on financially by a thread. Besides, they don't have a model that meets your stated requirements. Also, their support and ink availabilty could 'dry up' at any time.
They're relatively inexpensive to operate, however, they're not very popular and especially out of the question as you require enlargements that go beyond snapshot (4x6).
By your comments, I see that you've very specific and intensive demands. I still would suggest basuically looking into Espon and Canon.
The overall cost vs quality is in favor of Epson. Mainly because as a photo quality printer, they're tops. I've owned 2 models of Epsons in 13 years. Ink use is high but overall the print quality is simply gorgeous and it is very dependable.
Epson Photo Stylus 3000 approx $600 (wireless connectivity and larger ink tanks) if you want 13 inch enlargements.
In addition to USB, the R3000 will have Ethernet and 802.11n wireless connectivity. A front feed, L-shaped paper path is designed to accommodate a wide variety of paper types. It's got the more sophisticated front control panel that allows computer-less printing.
Epson Stylus Photo R2000 @ $490 (wireless connectivity and USB and makes 13 inch prints)
As for Canon Pixma inkjets, I'd recommend for you to research more than I can provide. Try review on CNET.com
http://reviews.cnet.com/printers/