A question about VHS and SVHS
You can't improve the quality of a bad recording. Especially if it is because the tape stock is flaking off oxide or is stretched, both of which are common problems with older tape stock. No matter what tape format you transfer it to, it will likely just get worse.

You might get about the same quality by digitizing with your capture card. However, you will likely need to use a fairly high bit rate, because analog artifacts have a tendency to cause low bit rate compression to induce even worse digital artifacts. If you use a low bit rate, expect the quality to worsen when you digitize it.