FO has been discontinued and about the only hope of getting a copy of Ver 10 is to find one on ebay or similar.
See http://www.rootsmagic.com/http://www.rootsmagic.com/ for information on RootsMagic. The interface is very similar to FO. It was developed by Bruce Buzbee, the author of FO and it will import all data directly from FO.
I know very little about Macs but do know there are Windows emulators that are used by some Mac users for RootsMagic.
The way to get user input on this and other RootsMagic questions is to subscribe to the RootsMagic mail list sponsored by RootsWeb. You will find many knowledgeable people on this mail list.
To subscribe to the list, send an email to ROOTSMAGIC-USERSfirstname.lastname@example.org with the word 'subscribe' without the quotes in the subject line and in the body of the message.