To be honest, an insane amount of printing, well, you just can't beat the labs. v.good quality and cheapest.
After that if it's just 6x4 then a dye sub printer, only if you need to print the odd picture bigger or you need to tweak your prints just the way you like them (perfect that is
) then look for an inkjet printer.
Personally I can't fault the IP8500 (I own one), but try to print pictures in batches or the printer goes thru a self clean cycle every time and ends up wasting a lot of ink!. the 8 individual cartridges are great, because you only need to replace the ink that has run out, and I have left my printer unnatended for 4 months in the past and not had any problems with clogged heads afterwards.
The IP8500 can seem a bit slow due to the wait between prints to allow the previous photo to dry, they fail to mention this in reviews, but the quality is superb.