Those should work. But I highly recommend using a method where you can adjust the spacing between omnis, at least until you are able to dial in whatever spacing works best before going with a mounting system where the spacing is fixed. You will likely find that even small changes in spacing between the microphones will rather dramatically alter the sound. Once the optimal spacing is determined you can then use a simple 3d printed non-adjustable mounting bar that provides that specific spacing, similar to the one above if you like. Such a non-adjustable bar can make for a more compact, minimally-intrusive arrangement in comparison to a fully adjustable mounting bar, which may be an attractive option there, and will serve to keep the spacing from being inadvertently altered each time it is setup.
Here's what I would recommend as a way of determining the optimal microphone spacing, and you won't need any bar at all to get started with the process. You can get a general idea of the impact of spacing adjustment by monitoring with closed headphones or in ear monitors with sufficient isolation during a rehearsal while altering the spacing between the two microphones. Fix one microphone in place and manually hold the other microphone various distances from the first while the music is preformed, moving it at 30 second intervals or something like that. While doing this, announce quietly into one microphone what the spacing is so that when listening back later you will know which portions of the test recording were made at which spacing. You can then listen back properly after the rehearsal to make a determination of what spacing works best.. and fine tune from there as needed. A note of warning- It will sound swishy with obvious comb filtering while your are actually moving the held microphone. Try not to let that influence too much what you are listening for when that microphone is held steady at various distances from the first. Make your movements in a determined way and hold the microphone steady for long enough at each spacing so that you have sufficient material to compare.
Once you home in on an appropriate spacing using that method, I'd make a longer test recording using that spacing, as well as one slightly wider and one slightly narrower, to confirm. You can use whatever temporary means you have available to do this such as taping the mics to a bar or wooden rod, using a second stand, or whatever.
In addition to dialing in the best sound for that specific scenario, this is a fantastic way to really wrap one's head around what's going on with a spaced omni pair in general. Most Taperssection concert tapers don't get the opportunity to dial things in like this for singular event, but it can make the difference between a decent recording and an outstanding one. If you are able to do this I suspect you will find it worthwhile.