Mac connection options for 2 old drives (with firewire, USB 2 and eSATA)?

Unsophisticated user here, please be kind. : ) I know they’re older, but I have two GD4 2000 GDrives that remain working well for me as alternating backup drives with TimeCapsule. I’m getting a new monitor to replace my Apple Thunderbolt and it does not have a firewire 800 port as the current one does. The GDrive does have a connection for USB 2.0 as well as eSATA. The new monitor’s two Thunderbolt “holes” will already be taken by the monitor connection and a Thunderbolt GDrive. The new monitor options include a blue SS “hole” (USB 3, right?) as well as a “USB UP” and USB SS with the typical USB-looking slots. Do I have any options here for a Firewire adapter that will fit in somewhere on the monitor, or? Otherwise, I’m thinking it’d be purchasing two new GDrives with Thunderbolt and daisy-chaining them somehow?

See, I really need some help…

Basically you can use the older drives on your newer system just over USB. The older drives are 2.0 but you can use that. FireWire was dropped a few years ago by Apple in favor of USB 3.0 and Thunderbolt. You can adapter FW to Thunderbolt but you are using the ports already like you said and you can’t daisy chain thru adapters.