I think the ADA "wedge" is a heating system.
The 30g I have is frustrating. Front to back dimension is very limiting. The top to bottom dimension means a lot of pruning for stem plants, especially in summer. I imagine the 40, which solves the first problem is going to be even more frustrating to work with in terms of top to bottom dimension, at least for stem plants. The 40 seems perfect for a low-level grass-lands aquascape. The 58 is surely the best option.
As regards moving, a 58 is no less convenient to tear down than a 30, or a 20. As regards land-lady's perception of size, they are all 36 inch widths. Make sure you get a flood alarm screamer nearby just in case. Renter's insurance etc. (speaking here as the president of a NYC co-op, I can say I know the ins and outs of these matters).
If moving is on your mind, then the most realistic decision would be not to buy until you have moved. When in the new lodgings, you can better see what type of tank can be situated where. Better still, aim for downstairs lodgings rather that upstairs.
Even better still, save the money, use the low interest rates, and buy something small (I mean a flat or house ;-) not a tank).