Gaara's much stronger than before as he now has the Shukaku's power with the burden's of the Shukaku. His pops who had the gold dust technique didn't just let him win, granted he was handicapped by being an Edo Tensei, but Gaara also has full knowledge of his mother's love now too. Personally, I think he was a bit arrogant against Kimamaro the first time, which was unsurprising from the pre-time-skip Gaara.
Kimimaro's not fighting for anything like Orochimaru as he was before. The latter is what really almost killed Gaara, was that Gaara was saying he was a fool for following Orochimaru and trusting him, etc. That gave him that last burst of chakra/stamina for the attack that almost killed Gaara and Lee if Kimimaro hadn't been ill.
Either way, they're in completely different battle fields, so I don't expect them to fight each other at all. Kimimaro might fight Mifune and some from his group, but Mifunes quick release crap won't be enough for Kimimaro like it was for Hanzou.
Peace