As far as editing on a PC goes, a 7200RPM disc drive is a must, regardless of size. 256-512mb of RAM should be adequate, as well as a decent processor (1GHz range).
With Firewire you should have no issues with dropped frames. "Capturing" from a digital source is a lot different than capturing an analogue sournce, in my experience at least. I'v never had any issues capturing digitally on even slower, poorly equiped PCs.
If you choose to get MiniDV, which is still prolly the best route, do yourself a favour and get an extended warranty. Repairing a unit, for instance, if the read or write heads loose their factory alignments costs hundreds of dollars. I paid $100 for my extended warranty and within months I had to have the unit fixed (it cost $318).
I use a Sony TRV900 at my work and it has held up very well on tape transport and play/record heads. However, the firewire jack is need of repair after frequent plugging and unplugging for editing. Just something to keep in mind in your usage.