What I have heard about the visa agent`s such as Bali Ide (
http://www.bali-expat-business.com ) is that they do not themselfs act like a sponsor, but they will hook you up with one. But if you wan`t to get a social visa before you come to Bali. (you have to be outside Indonesia to get a social visa issued) It might be abit tricky.. if you don`t have any conections like an Indonesian citiz. that will be able to be you sponsor.
Regarding the rent of a house.. I`t all depends on your budget?? but I would recomend you to wait untill you arive here in Bali, check in to a hotel for a few days and go on househunting yourself. there are many "house for rent" kind of signs/posters to find in Seminyak, Kerobokan, Canggu area, and also there is the bali advertiser that has it`s own section with rentals of house etc. By doing this you will skip the middleman and save a few(or alot) rupiah, also you will get a "feeling" of the place like you can`t by watching a picture.
good luck :D
