you can always get your build sheet then go buy your mdf ay Lowes....They will give you the first cut free on their big panel saw then they charge about 50 cents for each additional cut....since they saw is a very high quality commercial unit it can cut very precise...but lowes only guarentees it within 1 inch due to the stupidity of the minimum wage workers...though they are usually way closer....a trick i learned is tip the cutter an extra $20 ...because that like a 3 hour bonus...and tell him you want precise cuts to these measurements...and he will be within a dimes side width on each cut...it works everytime....there you got your wood and a custom box all cut out for about $60
yeah thats what i did last time i tipped the guy 10 bucks and he cut them out pretty nicely i just screwed up on the box itself really badly. there were like air leaks all around the top piece and it was pretty bad