Thank you, Jean, and again Erica! Comments about experimentation rings very true, and it's not likely anything I do at this point will "make it or break it," since the rules of my universe will be changing measurably regardless of my choices. I got excited and ordered a Curv-E, ink, blotter paper and some nibs, informed by Michael Sull's suggestions in Learning to Write Spencerian Script, prior to seeing your replies I ordered Higgins Eternal Ink, Gillot 303 and G nibs to begin, and have been really enjoying Claire-Fontaine paper from very early on. As for the Curv-E, I looked for medium grip, not super long, and just slightly on the heavier side, because ... caveman! Oh and, of course, in a model most appealing to my aesthetic, although there weren't any I couldn't love -- what beautiful writing instruments!!
I imagine it will take time with the new tools and supplies before I'll even be in a place to have personal judgements whether one thing works better than another for me. I've avoided extremes in my selections for now, and down the road, if I'm having regular problems with anything, I'll post questions and try other materials and most likely will then have a better sense of whether the new things are for better or for worse.