Another tube tester question

I was reading the other post about a tube tester. I need one also, but after
going through all the tube testers for sale on ebay.....I realized I have no
idea what to get. Some of them say they will check almost all TV tubes, but
does that also mean they will check Jukebox(radio) tubes as well? What does
mutual conductunce mean? Ive seen that on several of them. Some seem to have
only 4 or 5 holes to check tubes in, while others have anywhere between 10
and 25 or more holes for tubes.How do I know what to get that will check the
tubes in my 1953 Seeburg and any future jukeboxes I get? If any of you
experts out there can shed some light on what I and obviously some others
here need to get, I would really appreciate it. Id sure hate to buy one and
find it does not have testing sockets for the tubes I have. Thanks in
advance for however can help me out with this, because I know nothing about
tubes at this point..........Mickey