False bottom - What size?

I am new to all extract brewing and have a question about false bottoms for mash tuns. I got 2 used 5 gallon coolers and need to outfit them for brewing. One is an Igloo and the other a Rubbermaid cooler (identical or very similar to ones northern brewer sells w/ their kits). They have 10.25" and 10" inner diameters, respectively. NB sells 9" false bottoms with their kits and I just want to make sure this is the correct size as there would be a .5" or more space between edge of false bottom and cooler. Wasn’t sure how snug they were supposed to fit or if this space is required for fitting underneath the faucet hardware. Any help on what size to order is greatly appreciated as I want to get this ordered and start making some beer!

The 9 in. one is correct for those coolers.