I have a 2003 mb sports b52 with the rear ballast only. Not sure how much they hold? 1200 or 1600? Any way I need more weight in the bow, instead of trying to cram three people up there(most of the time we are just 3 adults and 2 kids) In what shape does the lead come , and where is the easiest place to purchase, and how much should i expect to spend? I am also thinking about a tube shape fatsac 600lb, but i hate to lose the space.