I just installed my FreeFlow Racedeck and I was able to rent a "flooring and siding cutter" from my local Home Depot for less than $30 for 4 hours and got all my cuts knocked out. Worked really well. May be an option in your area.
I also have the 72" heavy duty box and have been really happy with it. I recently just bought another 54" heavy duty box to go with it. I'm just a home DIYer, so it doesn't get abused but overall has been great. Drawers feel good, has a double glide main drawer that holds all of my heavy...