If you go with Premiere, it will handle everything from import to editing to export. I use Streamclip if I just need to convert a file or a batch of files. It's great for that, and very quick. HDV Split didn't work for me, but I was having general Firewire problems when I tried it.
One more thing, I always turn off my anti-virus (Kaspersky) while capturing HDV in Premiere. I have had crashes with other programs running during capture (and only during capture).