my mac has10.5.8 and should be compatible with new HP officejet pro 8600. I can't get it to install for wireless, nor to work with USB cable. Have tried downloading HP install directly from HP and it still doesn't work.

I just bought a new HP OfficeJet Pro 8600 printer. I have been unable to download the installation for wireless connection even though have had the assistance of Costco tech, HP tech and some advice from Apple. Because the system is MacOs 10.5.8 the error says it is incompatible, even though the product lists compatiblilty with 10.5, 10.6. I was advised 1 option might be to obtain Snow Leopard for installation, however am somewhat reluctant as the bo states 10.5 should work and Snow Leopard is 10.6, which is also listed as compatible. I am unable to get the printer to work even with USB cable. Too much time spent on this and I hate to start over with another printer because I'm afraid I might have the same trouble. Is Snow Leopard something I should get anyway? Help!