Long term rental agencies - recommendations?


Hi all

My 2 year lease is coming to an end, and we'd like to find somewhere a bit bigger. Looking for unfurnished apartments, and from scouting around the best property seems to be available through rental agencies, who all seem to want a depressing amount of commission (2 months). Soloduenos.com puts you in touch with owners directly, but the prices on that site seem very "optimistic" for whats on offer.

Does anyone know any decent rental agencies who charge less than 2 months commission? Or any other sites that have owner listed properties?

Thanks in advance