Be very wary of XLR<->RCA conversion. XLR to RCA is often "ignore pin 3". RCA to XLR is often Live to pin2, Signal Ground to pin 1, GROUND PIN 3. Thus the rest of your amplification is single ended as a balanced input signal bypasses the phase splitter!
XLR's true advantage is in eliminating common mode noise - the idea is that any noise from the environment affects the signal conductors equally and so cancel out. Hence being ubiquitous for microphone cables where the signal is very small.
You can always try stiff from The Cable Company Library.