Framing in a Breezeway/Carport for Master Bed

Hi All,
Only posted here a couple times and it was a huge help. The basement is done and we LOVE it...so thanks for answering my (and others that I read) questions.

Now: We have a ranch home that was built in '52. Between the house and the garage there is a breezeway that is completely wasted on us (well, actually, we keep our recycling bins there so....). My wife and I are looking to start a family in another year or so and would like another bedroom in the house and this is the natural (and less expensive option) place for it to be. My question, I guess, is the preparation of the space for framing/structural aspects of the job and the actual framing, itself.

If looking from the front of the house, the space is 11' wide by 25' deep. There is a concrete slab in there now that rises above the ground by about 5' at the highest point (not sure how deep it goes down). It is in relatively good shape besides a crack that runs from the garage to the house, right in the middle of it. Our house is on a foundation that rises out of the ground probably about 1' but with the joists inside and hardwood flooring, the floor inside the house is about another 6" higher. The garage floor is the same level as the concrete slab in the breezeway and has concrete blocks all around it (2 blocks high) that the studs for the walls sit on. Just about where that crack is in the floor, is a crack that is in those blocks too.

Luckily, my father-in-law is very handy. He's done a ton of work on this houses over the years (additions, kitchens, etc.). Another stroke of luck is that his best friend is retiring next month, owned his own construction business, and wants to do projects to keep himself busy while only working a few days a week (and picking up some extra cash). They've both said they are going to help with this addition but I want some outside opinions on it.

I assume (and they've agreed) that we would run joists from the house to the garage for the floor. The FIL said 2x8's, but I'd rather be safe and go 2x10's (or even 12's). Opinions? Do we need footers to span this 11' feet? I would think it couldn't hurt to provide more of that stability. I've been in additions and on decks that feel bouncy...don't want that. The space will hold the bedroom, master bath, and probably the washer and dryer in a closet in the bath.

Do we need to repair the crack in the concrete? What about the one in the cinder blocks?

Thanks for your help!