i'd like to use an external hard drive for ingesting files (i'm told this is the ONLY way to use Vegas or any NLE properly), but i don't know what drive would be best. firewire or USB?
But many users do use external drives some or even all the time, including me. Some prefer firewire, stating that transfer rates are faster, despite the marginally higher theoretical rates offered by USB-2. There is some system overhead with USB transfers -- particularly when more than one USB device is in use -- that results in these slower speeds.
That said, most of my drives are USB-2, because they're lower in price and because I've had a couple of nasty surprises -- sudden death -- with firewire drives. I think the best choice, overall, is a drive that will connect by either method; that provides ultimate versatility in portable situations.
Any USB-2, firewire, or internal drive will do. DV video data rates are not that demanding, by modern computer standards. Get a drive that fits your budget and start capturing.
since i ingest with firewire, i'm assuming that i may want to use usb for a drive.
I can understand why you would reach that conclusion. You'd think the Firewire connection would be "clogged up" with the incoming data. However, there is so much bandwidth, that the expected traffic jam doesn't occur. DV data rate is 25Mbps (notice the small "b"). If you use the big "B" (meaning Bytes instead of bits) this is 3.5 MB per second. The Firewire connection is capable of 400Mbps (50MB/sec). Thus, the incoming DV data stream only uses about 1/16 of the theoretical capacity.