It's certainly possible to get a Telefunken preamp... they're all over eBay. The problem is, they're usually not self-contained so you will need to provide an enclosure of some sort.

Also, don't limit yourself; Telefunken has a deservedly great reputation but it is far from the only choice for preamps, tubes, or mics. There are hundreds of great-sounding preamps around.

Electrical Audio has a large number of preamps, most of which are in the $1000-$3000 price range. However, they have some much more inexpensive ones (see the "Outboard" section of the Equipment index on this site) that should work almost as well...

Hope you find a good one...

Dan