Without a doubt run two single reels. There may be a tremendous amount of drag reeling two heavy teasers at once, depending on the teaser. I like the Reel Colors Teaser.
There is also a small boat teaser bracket which holds a Penn 114. The Penn 49L reel that everyone uses is discontinued.
I would suggest installing a third set of adjustible outrigger lines with a 1" stainless ring through which your 400# mono teaser line runs inside. This will allow you to adjust the position of your teaser in relation to your inside rigger bait. On the rigging, you can also use small turning blocks instead of glass rings which drastically reduces the friction. I have found that this setup is optimal. Placement of your teaser rigging loop is just inside your inside rigging loop.
Teaser placement is dependent upon your boat. Look for clean water and determine which wave placement works best for your boat. Your boat will be different than others.
Here is a cool