The only video card that does RT Matte Genretaion is the Aurora Igniter RT Card. There are two option for you if you are using cinewave, they also vary in price.
Option 1:
If the utmost in quality is the issue and you are uisng SDI I/O there is the EVERTZ Standard Defintion Rectilue Generator. This will make mattes, safe area markers, crosshairs, etc. all user definable. It runs about $ 4500 and is SDI I/O. It is a professional piece of broadcast equipment and you can check it out ar
http://www.evertz.com. the model number is 9590.
Option 2:
If you are just making preview copies and want to kill keycode and timecode or just have a clean matte, there is the Horita MG-50. This will generate mattes, all user defined also. It's I/O is only Composite Anaolg BNC. It runs for $ 289. Check them out at
http://www.hortia.comEither one of these units would be placed between the ouput of the cinewave and your deck.
Hope this helps