Get 3 switch each floor should have its own small switch and all u need is 2 run on cable form on switch 2another then plug the computer into the switch on each floor also get 3 printer switch 1.
Connect a switch per floor.
If you can t afford 25k then get any two 24 48 port dell switches and put them on 14 and run 4 1gb copper 6a cables between the switches 2 per switch going to each switch on 17 and port channel then for 4gb throughput and redundancy in case a switch or cable dies.
In this case you buy an access point for each floor.
Devise vlan names and numbers for the hr it and sales departments.
Pick one of the switches to connect to the 1941 series router.
Assign one department to each switch.
Plan the vlan scheme.
So just get a pre terminated cst armoured fibre om1 62 5 125 is more than good enough.
Or for wired solution one switch for each floor then good luck to wire each office or open space.
For each of your port on your router will be connected to one floor.
If you want to keep costs down go for lc to lc connectors go straight into you sfp module you will need to buy and then you don t give the model of your netgear switches sfp into new or existing switch.
You have sfp slots on the 6048 switch.
If you miss ports you buy a switch and you connect the switch always after the router.