If you need really long exposures, Provia has excellent reciprocity characteristics. I've done multi-minute exposures with no major issues.
(anologuers stop reading now, but this is relevant for posting gallery & example shots to APUG)
Have a look at the gimp and imagemagick for free high-quality resizing and other editing without watermarks. They work fine with gigapixel images (enough for 4x5 and 8x10 scans) if you have the memory; if you don't then they just run slowly due to paging stuff to/from disc.