What specifically have you tried?
My only experience is with a C&H Oval Cutter, and a Computerized mat cutter.
The C& H will do a good job, and can likely be found second hand for a few hundred dollars. It does take up about 3'x4'x1'.
The computerized mat cutter would be larger and cost more.
How much space do you have, and how much are you looking to spend.
If this is for 1 project, then subcontracting this may be the best option.
If this is a recurring project, then you will need to find an appropriate tool.