Sadly, I would say that Ringo has the most probability of ending up with Ikki because that's usually what happens in these kinds of stories.
Kururu, I thinks he's just going to remain a tuner who feels for her king. Simca...well. Somehow, I picture her letting Ringo take Ikki or something "noble" like that. She doesn't seem very involved lately (well duh, wheelchair)
Speaking of Simca...in the recent chapters. This brings me back to my question of how Simca could possibly have no battle skills whatsoever. Isn't she one of the gravity children, and Kilik's twin, to boot? I know that doesn't necessarily mean anything, but on page 111 of ch. 150 (volume 17, I think) they were seen riding up and out of wherever it is they were.
From the very beginning, they showed Simca "training" and Ikki watching. If she has those kinds of AT skills, I wonder why she isn't capable of fighting, according to Ringo.
And...I just don't like Ikki. >.> I don't like the whole "main-character-is-stupid-and-crude-but-he's-still-great" blah blah crap. I like the dignified type of king, like Kilik, Agito, Spitfire...even Rika. And...Ikki's really freaking whiny in the anime. Makes me want to castrate him. Argh, I don't really know how to say this, but I just don't like the "Ikki-type" in manga. Another example is Recca from Flame of Recca. Tokiya could've done much better. DX