I believe the largest commercially available notebook drive is 200GB, but even then, the only manufacturer is Toshiba (which isn't bad, but just cuts down on competition). If you want one that big, here's a link
I'm not a big fan of TigerDirect. I would much rather shop at Newegg, which has a MUCH better return policy than TigerDirect. I know, you have to pay tax at Newegg, but I personally find it worth the fact that if anything goes wrong with the product within a year, Newegg will replace it no questions asked.
Xmarlton, that Seagate is not the one you want either - MacBooks use SATA interface or Serial ATA - need to make sure this is what you get
If it says PATA, ATA, ATA-150, EIDE, or Enhanced IDE this is not the one you want.
Seagate does make that drive in SATA, though not on Tiger's site. They do have the Hitachi 160GB.