04 22v fat sac question

[guedo8]

Looking to add some fat sacs. the rear locker in my boat is roughly 38 x 22 inches. The Pro X Series V-Drive Wake Surf Sac dimensions is 42 x 16 x 16. Is it acceptable to allow the bag rest on the inner part of your boat? Or do you want it free standing. For example, the MasterCraft X-2 Rear Sac dimension is 32 x 18 x 20 which will fit fine in the rear locker (with room to spare) and holds an additional 50lbs. If I get the X-2 Rear Sac will the Valves cause a problem for me if I get the intergrated bow sac. The valves for each are differeny according to the picture. Any information will help. Don't know much about this area of boating.

http://www.fatsac.com/FlyHigh/FlyHighSacs.html