I was also looking for a good power supply, for my CMVS MV2F and found a cheap power supply that suits me completely.
All power supplies, which are in the photos, work well with one cartridge inserted into one slot. If you insert the second cartridge into the second slot, then the power supply is not enough for normal operation.
All the power supplies, which are in the photo, except the last (rightmost) are not suitable, for working with flash cartridge NEOSD. With these power supplies, there will be problems with burning roms in the memory of the NEOSD cartridge. There will be such a problem here, as in this video:
https://www.youtube.com/watch?v=OKKCJGb1QBk
I solved the problem of the power supply unit, by purchasing an inexpensive power supply unit for 10A. I bought a power supply and was pleased with it. I can recommend it to purchase:
Model: YU0510 (5v, 10a)
I purchased a power supply from this seller:
P.S.
But this unit also does not work with two cartridges at the same time, but it works perfectly with one NEOSD cartridge, I tried to recreate an error with the burning roms in the flash of the cartridge, but I could not repeat the error - everything burning roms perfectly and there are no errors.
Good luck!