@JDRoberts is spot on here with regard to Vesternet, note that I have no ties to this company but I fully rate the guides they publish and I personally use them because they provide great help and support.
With regard to this question:
If I use the Fibaro dimmer module is it compulsory to use a momentary switch rather than a standard on/off switch?
I believe the answer is no you don’t, have a look at the guides at Vesternet, start here for a single switch:
and look here for 2-way: