DJ, while you can print odd sizes on an Inkjet, few if any standard mat and frame sizes conform to them ... forcing you to print to conform or pay for custom mats and framing, which isn't an option when preparing a show due to the expense.
Same for the work I do destined for wedding albums. The mat and book sizes are set up for 5X7, 8X10 and squares. Recent addition of a 7 X 10 option insert mat has helped ... but still a vast majority of clients want 8X10s when ordering album prints or reprints and display prints like 11X14 or 16X20.
Same for Commercial work ... the standard is the 8.5X11 page format with squares as the second most used format.
Joseph, scanning is an art that requires practice just like darkroom work did. There are different techniques for different negative qualities.
The Imacon scanners are the industry standard for table top scanners, but are a lot more expensive. The Imacon 646 is around $10,000. USD. In return the 646 produces virtual drum scan flatness with a higher ppi and a true single pass scan D-Max of 4.6 ( some scan makers claim a 4.0 D-Max, but don't reveal that figure is a multi-pass scan number). Imacons come with Flexcolor software which is the same as that used for the big Imacon MF digital backs ... so it is very sophisticated compared to lesser scanners.
I currently use a Minolta 5400 for 35mm, and a Minolta Dimage Scan Multi PRO for Medium Format work. I also use a Epson 4870 flat bed for scanning 35mm and MF contact sheets and to scan some MF films not destined for big enlargements.
There are other options for scanning software like VueScan & SilverFast ($190. USD for DiMAGE 5400)
http://www.nextag.com/LaserSoft-Imaging-SilverFast-Ai--zz59585165zB2z2--COMPARE-PRICES-html
But optical prints from films still produce superior looking prints mostly because of the harsher light source in a scanner compared to a diffused light source in a optical enlarger.
There is a bunch of Minolta Multi Scan users that alter the light source in that scanner to produce much more pleasing scans with less pronounced grain edge. The recent Imacon Commercial level scanner ($20,000 ), has finally introduced a diffused light source.
The other thing you can do with your 5400 is do multi-pass scans, they take longer but produce superior results. Multi-pass is an option you can select when using the software that came with the 5400. There are other techniques like double scanning ... once for the
hightlight areas and once for the shadow areas ... then merging in PhotoShop using layers and masking to produce much better tonal range that is there in the neg.
Finally, what you see on a computer screen is harsher than what you will see in a print because a screen is projected light compared to reflected light of a print.