bench to buckets - need advice

[Montana '70]

Hey guys, new to the site and am clearly out matched by some of your rides. There are some amazing machines on this site. I'm wondering if anybody can give me some advice about removing the bench seat in my 70 Chevelle and installing buckets. Looking for some good seats with 3 point belts or a harness. Looking at Corbeau with the retractable set up, but it looks like it eats up the back seat. Just wondering if there is any way to mount it to the floor or if there are seats out there that utilize a different system.
Also, are there belts for the back seat that utilize the 3 point belt so I can take my kid for a ride. Any info is appreciated.