If the board is very bouyant you'll need a lot of lead which is a pain as pete says,being from europe we use different woods than you guys in the states but for most of my gliders i use beech which doesn't need to much lead,i'd guess an equivalent wood would be maple or cherry,most gliders are weighted at either end about an inch in,you can weight it centrally with one weight but i find it a pain to get right to be honest.