It's probably easier to keep heat out than to cool heat after it has gotten in. If the environment is hotter than you are, a fan won't do any good and a vapour phase cooling system is needed (picture a refridgerator on your back).
First priority should be insulating to keep hot and cold out, while keeping the temperature inside the suit in.
Then worry about active cooling/heating...which you won't need to worry about because the only time that is needed is when you are going to venture out very very far into the extreme areas for long periods of time and couldn't return to a room temperature area very easily (situations like this don't exist on Earth). Have it more be of a thermos suit instead of a heater/air conditioning suit.
What you are trying to do is not cheap (think astronaut suit).