Hi Mike.
I'm not aware of any such service but if you have any specific questions I'd be happy to answer to my best ability. I live near Novi Sad, in Vrdnik, Fruska Gora national park. (Btw, If you'd be interested in renting a new and modern 1 bedroom house in Vrdnik, I've got one available. There is a frequent city bus between NS and Vrdnik, so one can do without having a car.)Â
As for banking, many banks are no longer willing to open accounts to tourists, i.e. people who don't have residency in Serbia... some may still do it if you convince them that you will (for instance) be buying a property in Serbia and thus need an account. However, non-resident accounts don't come with online banking nor with debit cards, as far as I know.
Feel free to ask any questions you may have.
Petra