I don't own the Toshiba DVR670, but from looking at the Toshiba website, what you have will do what you want. You won't need any extra converter boxes. You will need to do a channel scan with the unit when you set it up.
The only problem is that VCR won't record in high definition. If that's okay with you, then you're all set.
If you want to record in high definition, an HD DVR, like the Dish DTVPal DVR would be the way to go. The DTVPal DVR has no monthly fees, can record two programs at once, has on-screen program guide, records everything to an internal hard drive so there are no tapes or discs to worry about, and recording doesn't result in any loss of picture quality. The only real downside is it costs more, about $300. I personally think it's well worth it.
Hope this helps!