Iomega, on their Jaz Drive Recovery page, suggests you use their Data Recovery service to get the files. I'm not advocating that, just putting that out there. They don't really want you to continue to use the old products.
Now that I got that out of the way, on their Jaz Drive driver page, they indicate you don't need drivers to use it... you need their Iomegaware software.
Drivers are small files containing the system files that allow your computer to recognize your Iomega drive. IomegaWare contains these drivers, along with special tools and important utilities that will help you format, protect, manage, and change settings for your Iomega Jaz drive. If you download IomegaWare, you do not need to download drivers.
The latest version of IomegaWare supports all Jaz drives. Features like read/write protection, copy disk, etc. can be found by right-clicking on your Iomega Jaz drive icon (option-click on the icon for a Mac).
Most operating systems will automatically detect your Iomega Jaz drive with native drivers. If your operating system is not detecting your drive, download the newest version of IomegaWare.
Now.... after ALL that nonsense from them, there is THIS page for the USB and Parallel port Windows 98 drivers.
However, if you would like to take their advice, Iomegaware 4.0.2 will work with Windows 98 according to this download page.
So, you have a choice there. Download just the drivers so you can see the drive in Windows 98, and then have no Iomega tools to manipulate the drive or data.... or download the Iomegaware software like they recommend.
All this information is courtesy of the Iomega web site.