Hi AUBEE'
No download site exists for the versions of the iWork applications suitable for your operating system.
Check Amazon, or other resellers of Apple software for the retail boxed iWork '09 DVD.
iWork '09 came in two DVD versions: the retail box version, sold with a 'single user' licence or a 'family' licence, and the 'trial' version.
AVOID the trial version dvd. It is essentially useless. After the 30 day trial, this versionshuts off the ability to print and the ability to save documents produced by any of the iWork aplications, and requires entering a registration number to restore these abilities. The server supplying registration numbers and the server authorizing the applications were both shut down several years ago.
The retail box version does NOT require a registration number.
You will need access to an optical drive capable of reading the DVD, and if this is not attached to your MB Air, you will need access to a version of Disk Utility (or another application) to make a Disk Image file of the DVD from which to install the iWork '09 applications.
After installing, and before running the applications, download and run the iWork 9.1 or iWork 9.3 updater.
(The earlier 9.1 version is described as "adds support for OS X Lion." If your profile information is incorrect, and your OS software is later than Lion, I would recommend only the 9.3 version—the last updater for iWork '09. If you are still running Lion, I would recommend waiting for additional advice on which version of the update installer to use.)
Both updaters are available on this page: Apple - Support - Downloads
Regards,
Barry