[H] Fetchlands (Mistys, Mires, Foothill) [W] Duals

have: 3x Misty Rainforest, 2x Bloodstained Mire, 1x Wooded Foothills.  Looking to convert them into duals.  Underground Sea is a high priority for me, followed by any other blue fetches aside from Tundra.  I'm set for Tundras.