interesting project. I've actually built a model rocket launcher that can launch up to 8 rockets at the same time either manually or after a preset time. This project is posted on my website:
www.personal.psu.edu/sdl162.
I have recently obtained a plc (programmable logic controller) and am in the process of programming it to launch model rockets. as for wireless you could use one laptop(remote) wirelessly connected through adhoc mode to your control panel laptop (master). u connect the remote pc using its parallel port and some programming, to remotely launch the rockets. u should be able to do upto 8 this way. u connect a 5v relay to each of the parallel port outputs of the remote pc. then u connect your input switches to the parallel port of your master pc. i'm in the process of setting a simular system up to remotely control the observatory dome on campus. hope this is of some help.