I dont know any in this area. but there is a slovenia website  http://www.nepremicnine.net/

This is more long term renting usally but sometimes they have short term renting also. Self catering is a great option in Slovenia. Food shopping can be really cheap. My weekly shop can be as little as 10 euros. Stick to vegeterain and you cut costs... also biscuits and cakes can be quiet expensive i feel ... so just live healthy .. and it will also be cheaply. you have three main supermarkets Mercator, Tus and hoffer ( Aldis to those from england).However make sure you go to local small farms for cheap eggs , and also small vegtable sellers ... amount of times they have given me a few free things i.e garlic.. bannas. There really kind and love it if you try ( even badly to talk in slovene) 

Hope you enjoy your stay. There is a wine called Jeruslem wine in the region were you are going to. The white is absouletly god sent.. and i dont usally like white . A must try. 

for more information on Slovenia go to www.inyourpocket.si

peace 

paddy