If you are going to be driving a long distance then you need to look into getting a bit more luxury and comfort. Depending on the climate, air conditioning will be a big consideration and the actual size of the engine will be a consideration. The biggest factor for long distances is fuel consumption and getting a heavy 4 x 4 if you are driving cross country is probably not the best option.
If you are renting a car for business travel, then maybe you need something a bit more stylish than the most basic rental car. In the business world, people judge success on things like cars and if you turn up in a cheap car it might create the wrong impression. There are rental companies that specialize in exotic car rentals and if you ant you can get the latest Ferrari and really impress your potential clients and business partners.
If you need more specific solutions for moving, traveling with animals or even traveling with ambulant disabled people then you need to make the rental company aware of that. Specialist car rental companies would probably be a better option as commercial companies usually have a lot of restrictions on what you are allowed to carry in the vehicle and doing so can cost you.