If the 20 long isn't suitable for the kinds of fish you want to keep and is just housing the lone zebra danio, better to rehome the danio and sell the tank now rather than move it, put whatever you get for it into the fund.
Can't be any help with the other questions.
Trouble with buying a stand before you move is that its best to measure the space you have for tanks before you buy the stand and tank. If you buy one to house both tanks now, then find you have an oddly shaped room when you get there and that it won't work... it could be a problem. Can you take the current bench thing with you for now to set the tanks up temporarily, then look at getting a replacement stand second hand when you're there?