Some of the bought tapes may have macrovision protection. If they do, the fastest, easiest way would probably be to run a vcr to a stand alone dvd recorder. You also need a video stabalizer unit in between to remove the copy protection.
Here are a couple
The second one seems to get recommended a lot here
Here is a little more info
As far as a stand alone dvd recorder, thats kind of like asking what tv or what car to buy. Do you want to spend 100$, 500$, 1000$? If you give a price range it might narrow it down where others can make recommendations. Personally I have never owned one. You can look up info on various models here
The other option would be to get a video stabilizer and transfer the video to your computer, then author and burn a dvd. Thats probably a more difficult approach, but it give you more option in the process. There are many different capture devices if you want to go that route.
Also try searching “vcr dvd” in the forums. This has been asked several times and there is a lot of info about it.