Re: Do I really need a capture card for editing hdv? Help!

Firewire drives are plenty fast to edit either the 1920 or 1440 MXF files from the EX.
Any NLE, including the really crap NLE's will output quality enough for broadcast. For giggles, we once produced a :30 spot for a traveling broadway show on Sony Vegas Movie Studio, a 69.00 application. It aired nationally on many stations. It was shot on HDV.
A lot of the answers depend on how you plan on processing the footage. If you feel you'll need to do a lot of color correction, then there is nothing wrong with planning for high end fibre channel raids and an entirely uncompressed workflow. If you're planning on shooting for style and won't be doing heavy color correction/retiming, then you'll be fine with a non-uncompressed workflow.
IMO, you don't at ALL need a card of any kind for working with the EX. We do have AJA cards in both our Apple and PC systems, and they're unused for this workflow. Having HD SDI output is a plus if you have an HD SDI capable monitor, but you're not going to find that in your 10K budget with computer.
Choosing the app you want to work with first is the first step you need to take. Everything else will begin to fall into place after that.
If you're working for yourself, no one should be able to tell you that X app is better than Y application. It's ENTIRELY personal preference. If you're working in a networked or multi-editor environment, there are some strong arguments to be made for Avid or FCS workflows. But at the end of the day, the output is the same from all the apps, outside of what you might do in the post process.

Douglas Spotted Eagle
VASST

Certified Sony Vegas Trainer
Aerial Camera/Instructor