The Epson Ultrachrome ink printers have good longevity and pretty good
color gamut. If you just need A3, consider the 2880 (about $550)if you
need high end photo quality color and black and white. However, if you
only require medium quality and a 4 color will do, the Workforce 1100 is
a pretty fast and cheap printer (About $150) and uses the Durabrite
inks, which are fast drying (and sometimes clog prone as a result) but
are rated for 105 years. The results, especially on the proper paper
are fairly nice, but certainly not as good as the 2880 which uses Cyan,
magenta, yellow, light cyan, light magenta, and three densities of black
ink.
Lastly, if you are producing mainly glossy prints and a few black and
white, there is the R1900 which is about $400. It uses Cyan, magenta,
yellow, red, orange and a gloss coating, plus two types of black, one
for glossy, one for matte finishes. It also uses the Ultrachrome
(Glossy) inks, which have a good archival nature.
All the Epson models are on sale right now with rebates (reflected in
the prices I quoted).
HP also has some Vivira ink printers which use archival inks, but I
don't know a lot about current models and pricing.
Art
If you are interested in issues surrounding e-waste,
I invite you to enter the discussion at my blog:
http://e-trashtalk.spaces.live.com/