Advice needed!!

I am planning a tackle box cake similar to these:
http://cakecentral.com/gallery/1756156/tackle-box-cake?sub=1756783
http://cakecentral.com/gallery/2258831/tackle-box-grooms-cake
http://cakecentral.com/gallery/2184107/tackle-box-grooms-cake

And I was wondering how much fondant should I buy?
Also, my plan is to carve the cake out of three layers using a 9x13 pan (hopefully I'm explaining myself right!) do you guys think that would work?

Thanks!

Any thoughts?