Honestly, if we knew for sure that you were going to get a bigger tank, then you getting clown loaches wouldn't be an issue.. but we don't know that you are actually going to...
IMO- If it was me, I would get the CL's- but then again, I also know that I have bigger tanks set up for them already. CL's again are slow growers... but you should keep a larger amount of CL's and you simply don't have the room.
SO I would hold off, and just wait. Remove the hiding spot for the Jack, and get him a terra cotta pot.. he won't hide as much.
In the mean time, just keep what you got, and enjoy!