Crossing the USA from Tampa, FL to Western USA and back

Thanks to everyone who has posted an answer to our request. It is all so helpful. I didn't see a place to post directly to a post in response with a question or simply a "thank you". We are new to this forum and you all are very helpful.
Our agenda is very open and time is not limited. Traveling from April to September and We'd like to travel approx. 200-300 miles per travel day.