Linux and Older Computers

[RedHat <redhat kchost net>]

I have some older computers the oldest being a 386 and I have a copy of
Linux 6.0. I would like to get some use out of these computers so I was
thinking I could install 6.0 on one and make it my firewall. Would this be a
good idea or should I stick with 8.0? Maybe set the others up as email and
bind servers?

Opinions please

Rick