But 24 inches of LMR-400 is probably overkill for just about anything. For that short a run, you won't see much in the way of difference between LMR-400 and something like LMR-200, RG-58, etc. LMR-400 is kind of stiff, so if you are going to use it for jumper cables, it's going to put a lot of strain on the connectors.
Are you sure you REALLY need LMR-400 for such short cables? Any difference in cable loss between 2 feet of LMR-400 coax and a quality RG-8x or LMR-240 coax has to be tiny. The LMR-400 coax is rather stiff to work with and finding BNC connectors for a large diameter cable might be a challenge.