We use nothing but BiDi SFP (one fibre Single mode fibre) at both 10Gig and 1Gig speeds (upto 120km!).
If you can get single span fibre cheaper than duplex, then go for single. The SFP's are quite cheap.
I would terminate the ends with LC-UPC (The blue connectors). This is what the majority of the SFP's use these days.