Power Specs for SX GBIC as from CCO:
Transmitter output power - (0/-9.5 dBm) (minimum/maximum)
Receiver sensitivity - (-17 dBm)
Receiver maximum input power - 0 dBm
Yes the more radical the bends the more light loss, you should really get and OTDR or at least a power meter.. as the loss's thru the patch panels are unknown at this point.
If you can get your Fiber cable specs this will help, as older fibre has a higher chromatic dispersion which will not help your cause.
You could use the LX GBIC with the 62.5um fibre, but be aware of the total distances, if you are below 100m and above 300m you will need a modal conditioning patch cord on the recieve end of each link.