I need faster realtime response from FCP5 for a production environment. Asside from having a Dual G5 2.7GHz, shitloads of RAM, fast storage, and possibly a good graphics card; would cards such as the Kona LS and/or Black magic help in getting more realtime out of FCP5?

Some cards such do support specific realtime effects, but to the best of my understanding (in other words, I may be totally wrong!) Apple has shifted FCP to depend on the system and not add on cards. Most of these cards are designed to add extra functionality, such as HD or uncompressed, not just pure speed for DV. From my experience, realtime effects are dependant on two things--raw cpu speed and the coding of the effect.