I think a lot has to be invested into an A.I. unit that will have to make real time informed decisions while its on the planet. The gathered data can be sent back to us on Earth (wow, that looks really strange after it's written) where we can then send out a set of overall orders that the A.I. will breakdown and form a new plan and strategy to follow using a rover and a drone unit together.
first i would place at least 12 satellites in orbit. basic gps stuff. couple ground rader. photo types.
then worry about a "flight" type of mars drone.
but the mars drone would maybe be a balloon lift style as well as props. this would give very long flight times.
larger drone (more test stuff). more solar cells? longer possible life?or heck with it all and put live assets in orbit. in a hab at least 100 times the size of the little hamster tube tinker toy in earth orbit.