Balanced vs RCA preamps

For me it was more about flexibility. I like having both because not all power amps have both. Also, I'm thinking about getting some high-end active powered speakers. I can use my existing preamp to switch between my powered speakers and passive speakers between both sets of speakers without changing cables. Balanced cables are supposed to have a lower noise floor especially for longer runs but I think in reality it doesn't matter that much for the average audiophile.

When using XLR connectors be aware that Japanese audio manufacturers use a different configuration for pin for ground.  

So if using say a US made pre-amp with a Japanese amp you need to make sure they are using the same pins for ground.  Accuphase amps have a selector for this.

Rogue Audio has tube preamps with both RCA and XLR outputs.  I have the RP-7 that has two sets of each, and I believe the RP-9 has the same.  I am quite pleased with sound quality achieved with my RP-7 and my Odyssey monobloc solid state amplifiers.

Spatial Audio Lab Raven Preampr Has some of each. 

I have not owned a single ended tubed preamp that did not produce unwanted noise over the cabling. I made the switch to an ARC preamp and was able to put balanced cables in all the way through from DAC to amp. Best move I ever made to significantly reduce noise and hash. Now I have a black background. If there are single end tubed preamps that are quiet, I certainly didn't have any luck finding them like some others have.

YMMV