Keyboard rental in Frankfurt? Bits?

[Rhodes54]

1. Going to Frankfurt for two weeks in March and I'm having a difficult time locating a place that rents keyboards. Anybody know any place?

2. Playing out live with Mainstage/Macbook, mostly small clubs and such. Will it make a noticeable audible difference to upgrade my audio interface? I'm using a little Behringer UCA202 via USB to my Macbook, and it sounds alright to me, but am missing something by not going 24-bit? It's just output, I'm not doing any input

Thanks in advance,

Stewart