Ibex is supposed to be coming out with a seamless camisole soon.
Smartwool has a tank-top.
Someone had a link to Icebreaker camisoles and undies.
<Knot goes to look for links>
Icebreaker tank top: http://www.backcountry.com/store/gro...ml?id=GRbK5xtX
Icebreaker camisole: http://lonelyplanet.altrec.com/shop/detail/30921/
Smartwool tank: http://www.teamestrogen.com/products.asp?pID=26644
Ibex tank top: http://www.ibexwear.com/shop/Product...ies-Sleeveless