The Thompson Elite post is actually in the ballpark weight range of many of the carbon MTB posts, so I wouldn't worry much about the weight there. Its an amazingly beautiful CNC'd anodized piece of aluminum. For stems, if you aren't concerned about weight, the Salsa SUL series always gets my vote. Very beefy with a smart locking lip to prevent the bolts from loosening. Otherwise, Thompson stems are as nice as their seatposts if you can spend a little more.