There was a RB750GL which is capable of routing 400Mbps about (perhaps a little more)I'm assuming you are referring to the RB951G-2HnD or RB750Gr3 specifically as they have gigabit ports. Whereas the older 750 and 951 are 10/100 ports only.
Would suck to have faster internet than what your router can handle (wait, what? In South Africa??)
HiYeah most Mikrotiks will do that. RB750, RB951 easily.
It's when you get to the 1Gbit speeds where you need to look at a RB3011 and upwards.
Also note that the fiber installed to your house is a SINGLE core fiber, which won't plug into any traditional SFP module anyway.Your FNO will install an ONU that converts fibre to copper. 9/10 times they dont allow you to plug the fibre directly into your SFP router, this is for troubleshooting, and probably most importantly, remote configurations.