Theatrical makeup is definitely a good option (I personally use an assault of Ben Nye products for school productions), but sometimes difficult to apply evenly over large areas like the arms. I would recommend a skintone bodysuit like this
http://www.cosplaysupplies.com/hosery/8578_resize.jpg that isn't too sheer. You could probably find one in a dance/gymnastic wear shop like Capezio. If you can find one in a color you like, that would take care of the pigmentation of your arms and back and you could match a theatrical makeup to the color of the suit for your neck, face and hands.
A suit is also a good option because it would allow you to wear a (seamless) bra to enhance your bust. Silicone falsies are a good move as well if you're dead set on the smoothest look possible. I think they sell a variety of bust-related support and enhancement bits and pieces you could sew into your costume at Joann fabric stores, but I don't know exactly what they have.
If you're not vehemently against alternative lifestyles or afraid of extreme crossdressing, it probably wouldn't hurt browsing around transgender websites to catch tips.