I use a range of tunings on a range of guitars, with string gauges to give me the tension to suit the tuning. Strings Direct will sell individual strings for this purpose (at least, that's what I use them for). The following gauges work really well for me on a small bodied 12 frets to the body steel strung:

1st — E        .011
2nd — C        .014
3rd — G        .023
4th — C        .036
5th — G        .045
6th — C        .060