"upgrade" to dated version of Pro Tools LE

[Jasari149]

Hi. I currently use Pro Tools LE v 7.1.1 (with an mBox2) on an Intel-based Mac running OS X 10.4 (Tiger, I believe). I'm not satisfied with the mBox2 and want to purchase a Digi 003 rack (and potentially get it modded by Black Lion), but I need at least LE v 7.3 to use the 003.

Is it still possible to upgrade to v 7.3 or 7.4? All I see on the Avid/Digi website are options for upgrading to v 8. I don't want to upgrade to 8 because that would require me to upgrade my OS and I don't want to run into compatibility issues with other programs unrelated to Pro Tools on the computer and I don't know if things like the Music Production Toolkit (1st version) will even work with PT 8. Will the MPT work with LE v 7.3/7.4? Does the Digi 002 work with LE v 7.1.1? If I got the Digi 002 modded by Black Lion, would it be much different than a Black Lion-modded 003?

This is giving me a headache. I'd appreciate any help/insight.

Thanks.