If that's what you're aiming for, you'll want to wait til all the +100% eidolons are released about a year from now. You'll need to do 32 10-rolls for a good chance at one (6/27 eidolons, multiplied by the SSR eidolon rate), or about 100k jewels. You'll likely get a good haul of SSR kamihime from that too... but will you even be playing anymore at that point?
The +100% eidolons are mainly aimed at whales. Average players shouldn't expect to get them through normal play. At least with SSR kamihime you can build a strong team with whatever you're given by Lady Luck, but most of the SSR eidolons are truly useless.