Are looking at big boards or inline Boards? If you are going with inlines, I would suggest Offhore OR 12 or OR 31 SST(salmon, striper, trout). Both of these boards are great for walleye fishing and other species.
www.offshoretackle.com
The Offshore OR 12 can be rigged a few different ways to aid your fishing that include, a Tattle Flag addition.
To answer the second question when you originally let your line out from the boat your lure will dive. Then you add your board to get it out from the boat.
The Precision Guide to Trolling book is a great investment to know how deep lures run with line out.
For big boards I run Big Jon Otter Boards. I use the big boards for musky salmon and trout fishing. With the large mast on the bow of the boat that fits in the seat base. You can find the mast at Offshore Tackle too.
_________________
Get in, sit down, shut up and hold on !
Bob Devine
www.chartertalk.com