There are a few options I can think of and it depends on the level of sophistication and budget you have.
For instance, do you want the blades to move at exactly the same rate and/or just arrive at the destination at exactly the same time? Or just arrive at the equal position, but not necessarily at the same time?
Usually in the CNC/control world, Stand Alone means the system does not rely on any other operating system to load first, as in a PC based system.
This then would possibly mean a Stand-alone 2 axis motion card system, like a Galil 1500 & Maple Sytems Operator Interface, a PLC (programmable Logic Controller) system with OP interface, or a PIC MicroController based system, the last of which is possibly the cheapest , but requires the most engineering.
Also, if you want to go with steppers, they would be the cheaper, but servo with encoders will give you position confirmation.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.