Hi everyone,
I've been looking for design ideas for a major exterior renovation to the exterior of our home. Home is a brick ranch over a 1-car garage. There is an earthen-grade with a gravel driveway up/around to the main living area on the right of the house and a 6" concrete slab at the top of this grade that extends for 18 feet out of 43 feet total length of house front.

The problem is, only half of the front entrance concrete slab is supported on a concrete-block foundation. The other half, as near as I can tell was laid on the dirt earthen grade and has started to sink on that portion of the slab causing a stress crack to develop in the slab about 2/3's the length of the concrete.

I would like to remove the slab, excavate earthen mound bordering drive around (but preserving the drive around)install 1-car garage where earthen mound was (close off garage in main basement for living space - next project;-) and build a sunroom or a simple covered deck over the new garage.

Does anyone know where I can get some ideas on design and construction of this type of project. Specifically, what are the alternatives to building materials for the 'roof' over the garage, which will be the floor for the deck/sunroom? I've considered replacing with poured concrete but that's probably going to be beyond our means for the size of this project. Alternatively, I've looked at some of the pre-formed roofing products that can be installed with a walkable surface on the top and there's also composite/wood decking.
But I just really need some design ideas and comparisons.
Sorry for the long post but thanks for the help.