Are any of those switches upstairs? If so try to place whatever router you buy upstairs so that the wireless signal can cascade down through the house, through ceilings rather than sideways through internal brick walls. Make sure, if possible, that your router is placed before all your other switches. If you go for my 8 LAN port router it could replace your 8-port switch to give you more flexibility.
So, when you get your new router, first thing you need to do is convert your SHub to modem only mode. Just type 192.168.1.1 into your browser address bar to access the Shub interface. Then log into the interface. You'll soon find the right place. Be aware that changing to modem only mode will change your WAN IP address. This isn't a problem for most users. Also the local IP address for your SHub will have changed to 192.168.100.1
When the SHub is in modem only mode all your pre-existing network function will be gone. At this point connect your new router to an ethernet cable coming from your SHub. Make sure it goes into the WAN port. The address for this for you to browse to should now be 192.168.1.1 By default the router will be in LAN Router mode. All you need to get started is run the quick internet setup wizard at the top, then we you are sure you are connected to the internet go to the next tab down 'Network map'. There you can set up wireless for both channels. The 5GHz channel is the one that will give you the best wifi signal, but only to 5GHz compatible wifi devices. I set both SSIDs with the same name and password for simplicity sake.
Routers normally come with default settings with firewall etc on, but do check. Go to the Firewall tab to be sure and particularly check that DoS protection is on. I enable "Respond ICMP Echo (ping) Request from WAN" so that I can monitor my network quality through a Think Broadband graph.
After that you should be set to go plugging in all your switches devices etc. and connecting your wifi devices. If all is working well and your ethernet cables and patch cables are CAT5e, or better, then you should get full download speed on all your wired-in devices.
Everything I have said so far will apply to General Maximus' router suggestion except that the AC68U has 5 LAN ports not 8.
Please don't feel restricted by our suggestions. There's plenty amazing routers out there. If you had had others respond you would no doubt have had other recommendations.
Here's a good site for Router spec/performance comparison. Have a look before you decide. Type the router you want to look at in the product search box.
https://www.smallnetbuilder.com/tool...=ASUS_RT-AC88U