Technically maximum length of 100m is not 100m of horizontal run; 90m of horizontal run and 5m of patch cables on each end. And there should not be any issue with 100base-tx because I am using 100m of CAT5e for my Fast Ethernet and it performs well(94Mbps and even 1ft is the same), but if you consider 1000base, I'd recommend a good quality MM fibre too.
If you think of scalability, a pair of optic fibres is capable of any transmission speed from 100Mbps to 10Gbps or could be faster as long as a module uses an MM fibre; you just need to swap SFPs or other modules. And no EMI issues as already mentioned.
If you think of scalability, a pair of optic fibres is capable of any transmission speed from 100Mbps to 10Gbps or could be faster as long as a module uses an MM fibre; you just need to swap SFPs or other modules. And no EMI issues as already mentioned.