Assuming you'll be insulating and adding heating/cooling I think the better question is not type of flooring you can do, but rather what kind of subfloor have / plan on building? You can certainly put tile above grade (as well as just about any flooring), but the real question is if your floor joists and subfloor are stable enough to support your desired flooring. Tile is certainly possible, provided the proper structure exists.

Personally in an office I would prefer carpet, wood, engineered wood, or laminate. But another option to tile would be is vinyl tiles.

Tile will normally be more than a wood floor. Laminate is the way to go based on your comments.

Thanks to both of you. The house is solid...floor joists will support anything.