My parents have recently bought a new VCR etc and were considering a combo. I personally advised against it due to the fact that if one breaks then you either have to fork out to get it fixed (approximately the same price as a single VCR or DVD) or pay for a totally new one.
I recommend buying a separate VCR and a separate DVD. (plus, as the prices are dropping on the DVD-Rs then you will be able to get one at a decent price) Also, I don't really think that VHS will die out that quickly - Cassette tapes are still available in major music stores and unless you have the money to buy a DVD-R or a Burner, then you would have to buy all your favourite VHS on DVD
I think separate is always better, as you have more freedom for upgrade and for replacement when one breaks.
Hope that helps, it is just my own opinion though!
Shame you aren't near me, I have a VCR that will be looking for a home soon!!