"I am unsure about the life of the prints..."

I've got an Epson 9800 giclee printer, and have been printing on fine art canvas (prints to 44" wide).  The output of this printer is stunning.  I coat the prints with a gloss UV protectorant after about 24 hours to dry (not a problem with porous media like canvas).  My minimum print resolution is 200 DPI, and I usually go for 240 DPI.  BTW, a great upsampling freeware is "Irfanview."  You can get it at irfanview.com.  This great little program will upsample images using high quality B-Spline or Lancos algorithims (as well as others).  This is an excellent way to double (or any ratio) your renders for final print.

The K3 pigmented ink for this printer will show no sign of fading inside a home with normal lighting for over 100 years -- without being behind UV glass or plastic.  If you are going to have a print service do your printing, which is certainly a viable option over forking out $5 K for the Epson (can get an Epson 7800 for $3 K though -- good for 24" wide prints), make sure the ink is pigment and not dye based (though HP now has a long-life dye ink).

The Epson 9800 is possibly the best -- at any price, fine art printer, for canvas and other thick media -- like posterboard.