Sorry, came in a tad late... haven't read the rest yet, so this is my knee jerk reaction.
Good looking proposed cabinet RL... though I like the old one (only for the wheels). After initial setup all is great, but if you're anything like me, upgrades are inevitable and then the cable exchange takes place, and we get family, neighbours and friends to help out.
Have you (or is it worth) considered a lazy-susan to get to the back of the cabinet? though a little neater.
If your first cut is too short... Take the second cut from the longer end... LBD