A good, economical, rack mountable replacement for your 600Mhz equipment is the Shure BLXR series of wireless mics. These are nearly the same as the BLX series but offer some more flexible integration options. They are rack mountable up to two receivers per 1U and have detachable antennas to allow integration with the Shure antenna distributions systems for multiple unit systems. This particular link is paired with Beta 58A capsule. Support us by purchasing through the link below!