Ultimate Ghost Rider - Ultimate Ghost Rider be a challenge but it could be done. Have Johnny Blaze be an unwilling test subject (probably to Ultimate Hydra). Hydra's experments would involve trying to make normal humans into mutants (Like what the Brotherhood tried to do in the first X-Men movie).
Ultimate Rick Jones - Ultimate Hulk is on the run and it's hard to do it on your own. So why not give him a partner? A teenage runaway? The upcoming Ultimate Wolverine vs Hulk mini is the best chance to intoduce Rick Jones into the Ultimate Universe.