Don't forget single cab vs. extended cab, the middle bracket is incorrect because the floor profile is different. Got some work to do there. The bracket is too tall because the extended cab has a lower floor. If you don't mind something that feels hack-ish, you can mock the seat in place, mark the bracket spot, and ... persuade... a dent in the floor to make room for the bracket. I've done this on low-buck builds where the owner just wanted a nicer seat in their work truck. I'm not proud of this.
Or, if the seat is manual, you can cut and weld the bracket to size. Power seat is a little tougher because of less clearance to cut excess material out of the bracket.
Be sure to back up your new seat bolts with LARGE thick washers under the floor so the bolts don't rip through in the event of a crash.
Richard