Don't worry about quality from an EP VHS tape because there isn't going to be any. If the tapes have been played a number of times, the quality will be even worse. Each time a tape is played, particles are rubbed off by the playback head and the quality of the recording gets worse(that's why they had head cleaners).
You need some kind of video capture device or TV tuner computer card. The consumer "video capture" cards were never very good. If you use a VCR and capture device, you should use a time base corrector as well as some sort of video signal processor or the captured video may be washed out and jittery. For compliant DVDs that play on standalone players as well as computers, you need to use MPEG2, which is way past it's prime. If I recall correctly, and I spent years trying to forget analog recording, you are looking at about 240 lines per inch video, which by modern standards, is really poor. No matter what you do to the video on the tapes, it's never going to be better than it is now.
You need to decide how valuable the content of those tapes are and how much you want to spend digitizing them. If I had to do what are considering, I would forget the DVDs, convert the tapes to MP4 and store them on a thumb drive and/or digital storage device including hard drives or SSDs. That way, you won't need to convert the DVDs again to something more relative down the road a few years.
If you have a computer with an AGP video motherboard, I think I have an ATI All In Wonder card with all the video capture accessories I'll sell you for $20, then you can relive the 1980's all over again.