Cecilia,
Your posts don't mention where you are, but if you are near any big city, you should look at Film Support houses. Many of the external power supplies offered to the music industry have, as J. Peacock mentioned, 2 or more channels. If you are working with this single mic in live entertainment, you may want the smallest, easiest to transport supply.
In the film industry, several companies offer small, battery powered single channel phantom power supplies. These are light weight, so they can be attached (with velcro, for example) to boom poles for recordists on sound stages or in the field. One can just as easily be velcro'd or clipped to your mic stand.
Local shops which cater to the film industry often don't have much to do with the live-sound industry.
If you don't have a local shop, you can go on the web and deal with Coffee Sound, or Location Sound, both in North Hollywood, or Wilcox Sound in Burbank. These houses are used to supporting film crews around the world, so they can probably fix you up where ever you are.
One word of caution, there is a really good battery powered unit made by PSC (I think it may also be offered under the Sennheiser label), called a Universal power supply. It is switchable to supply either phantom or 'T' power. This is useful for film people but NOT useful for you. The 'T' power option just costs money, and won't work with your KMS-105. Get a straight phantom supply, not a Universal one, or you will end up one day with the LEDs glowing and no sound because a switch accidentally got bumped to the wrong position (OK, so that was more than one word!).
Cordially, Tom (not affilliated with any of the above, but have done business successfully with each of them.)