I believe I answered your question (sarcasm aside)...... as well as Rubicant. And the discussion between Mofokubik and Rubicant, answered them too....
A Summary would be:
Those files you found "are" Soundfonts, in a way. They are DirectX Soundfonts, and have nothing to do with "Creative" or "AudioHQ" (except maybe for that synthgm.sf2, but lets not go there.). None should really, concern you. Especially in any type of loading order, or the size....
FF8PC does the loading for you, without any problems...no workaround to solve in getting better music into FF8. It's just a simple overwriting of files, to get better instruments.
Read the bottom of my previous post..... Then just use Samuel Slight's FF8 patch; I left you a link. There should be a readme file in that download. And if there isn't, you just need to unzip the patch in the directory where FF8.dls is in.
Like I said before...you have to, sometimes, read deeper, than just the surface....what's "amazing", as you put it, is that you didn't.