Our dog had CCL surgery and has a real hard time on our hardwood floors. We've tried putting rugs all over the place but he'll find a spot that's not covered and plonk himself down and then have a hard time getting back up because he has no grips on his paws. I'm looking for boots that he can wear around the house. All the websites show boots that are more specific to extreme weather situations.
He is an 80lb lab/retriever mix.

I personally like the soft fabric types with velcro. They will have rubber spots or strips underneath similar to babies socks. I like the soft fabric type as opposed to the actual boots as it's much easier for the dog to get used to wearing them.
You can even make them yourself out of babies socks and some velcro or elastic, minimal sewing skills are required.

Alternatively you can also buy non slip paw protectors that you actually glue onto the bottom of the dogs feet (with skin-safe glue) to stop them slipping.

Lab/Golden Mix? Does he have long hair between his paw pads?
The hair can make things slipperier-er, you could try trimming the hair under his pads DO NOT USE SCISSORS. Let a groomer or technician at his Veterinarians office show you how to trim it with clippers. And keep his nails at a comfortable length, this will help if he decides he doesn't care for the booties.

If this a recent surgery I would suggest limiting his access to the whole house and have him stay in the rooms that you are in so that you can assist him with a sling until he is able to get his footing and go it on his own.
One wrong slip could cause quite a bit of discomfort and possibly do damage to a fresh surgery.