@Kenneth,
I assume you bought iWorks 09 as a download from the Mac App Store? The iWorks applications will all be in your /Applications folder on the Mavericks machine, and also backed up on to your Time Machine volume. When you get your new iMac (presumably w/Mavericks), the iWorks '09 applications will find their way into the new /Applications folder when you run Migration Assistant to copy all your files from the TM dataset on to the new iMac. If not, you should be able to copy the iWorks apps from /Applications on the old Mac to /Applications on the new iMac. (that's assuming that you still have the old Mac available). You could network the two machines together for the file transfer, or copy them to a USB memory stick.
It would be a good idea to seek out the three iWorks '09 applications that are in oldMac/Applications and zip them up into an archive (using the Compress... command). That will give you an extra safety net just in case Apple should see fit to delete the iWorks '09 applications from your Mac as part of an "update".
Another way to get the iWorks '09 apps (assuming you bought them from MAS) is to use an Mac running Mountain Lion or Lion. Log in to MAS using your AppleID, which has your purchase of iWorks'09 registered. As of last weekend, I found that MAS would happily download Pages 4.3 (which is the version of Pages in iWorks'09) onto a ML machine. I presume it will do the same for Keynote and Numbers, though I have not tested it. Once downloaded, you can then copy the '09 applications over to your new iMac.