I'm an idealist. A lazy one. So I don't very often commit to a task even if I believe in it.
That said, my proposed objective would be to get everything. If you're truly altruistic enough to do it, don't pick and choose; go one by one, start to finish, alphabetically. It would be unfortunate to miss that one oddly named cult-classic plug that nobody remembers by name. To save some time and effort, yes, bundle them up into packages (but don't put them in the same plug-in, just the same compressed archive). EV Addons A-Z; EVO Addons A-Z; or however many sections it need be split. A very important thing to add to each archive is an exhaustive list of the contents of all packages to help people find what they're looking for.
At that point, you will have done more than anybody ever expected of any one person. Let somebody else decompress them and re-package them if they want; however, I suspect that the folks who want these plugins converted will be the folks running a modern enough computer that a few gigs (if that) of superfluous data is a very minor inconvenience to get that one diamond in the rough of which they've been dreaming.
As far as having a classic Mac to check everything on, I have one, but its space is severely limited (~600mb left). Moreover, I'm an amateur in the extreme, so I hesitate to claim I can look over a plug and verify that it came out alright. I had my few favorite plugins, but even then I didn't commit every detail to memory to even a tenth the degree I did the stock scenarios. Failing anybody else to give them a dry-run though, I'll volunteer for at least a few. Each will definitely take me quite some time to get to and play through. It bears repeating: I'm lazy.
Finally, regarding Age of the Council, I was not aware that it was still under development; much less that EVWeb was now project head and looking for a few hands. I think I'll drop him a line and see if there's any unimportant busywork I can do for the project. Maybe go through the files and label everything or something. >.> I am very glad that you mentioned it.