Multimode, up to 40KM, but it really depends on the cable... Either way, max length you're talking kilometers, not meters...
Media Converters, everyone sells them... Planet's are about R500 or so (you need two - one for each side). R850 odd for Gigabit Ethernet to Fiber converters
Last time I baught fiber (years ago), 4-Core was about R8.50 per meter (I would expect that the prices came down since)... Any good reputable company that sells computer cabling will be able to get for you (I got mine from Falcon Electronics back then), but make SURE it is OUTDOOR fiber, NOT indoor fiber. Outdoor also has ALLOT more protection to protect the fibers against breaks, but it is more expensive (could easily be double the price)...
Moisture from the air will get into indoor fiber if used outside, and it will deteriorate the signal. Get to a good supplier and chat to them, they'll help you out on everything you need. It sounds complicated and expensive, but it's really very easy once you get your head arround it.
I did a 2 x 4KM 8-Core Fiber runs about 6 years ago, for under R10K, cable labour, trunking, etc etc etc
You didn't mention where you stay, so I can't really make any recommendations to suppliers in your area.
PS: It's not really worth it buying 2-Core fiber, the price difference between 2 and 4 Cores are insignificant. 4 Core also means that you have 2 Cores (or 1 pair) spare, incase you DO one day have a break... Then you simply switch the broken core to a spare core, instead of having to replace the entire cable...