I'm in the process of redoing my old truck and I've wondered about mirrors too. When I first did this truck in '84 I didn't like the big mirrors on it (beat up trailer mirrors with white arms) but didn't want to use anything small. I used Dodge truck mirrors instead. Chrome, rectangular but with the arm going through the side of the housing instead of having the exposed bolt on the back of the mirror housing.
As the bodywork is slowly getting done and ready to go back on the frame, this issue pops up in my mind now and again. I really like the visibility these Dodge mirrors offer but I like the asthetics of the round ones posted above.
These were the best pictures I could find right now. This was just before the truck got taken apart.