I won't lie, you'll certainly have to buy a lot of Clear Spheres (about 400), and you'll have to use one of the better ap farming methods (the Don Tonberry method can easily amass over 99 SL at once, although there is a cap); you'll also need an efficient method of farming Strength/Magic/etc Spheres (using a Distiller or one of the Distill abilities on Kottos and then overkilling him yields a guaranteed 40 [unless he drops 2, in which case it would have been Dark Matter...whoops]). But it's not too tough, really.
Although I'll also be honest, years ago, I printed up a few of my favorite faqs at Gamefaqs and kept them in a binder, to which I added all my personal notes on the game itself (which I recently found and have been going through). I'd be more than happy to link to any of them if you'd like (the Don Tonberry AP farming method in particular is exceptionally handy!).
Stuff like that is how I did a lot of my own independent research - like finding the most efficient method of consistently getting Yojimbo to perform Zanmato (I won't bore you guys with the details but I love behind the scenes mechanics like that and figuring out the best ways to use them - it's actually a lot of fun for me).
I'm rambling so I'll stop talking now, after I say that I like tedious stuff like that so I could be biased ;.;