It's Vivitar, not Vitar.
Vivitar was a brand, not a maker. The quality of a Vivitar lens depends on who made it. Old good Vivitars were made by Komine, Kiron, Tokina. You can tell the maker by the first two figures in the serial number:
Vivitar Lens Manufactuers
The obvious difference between the two is that the Konica is a prime lens (fixed focal length), while the Vivitar is a zoom. In this case I'm sure the prime beats the Vivitar optically.
However, you first have to make sure the lenses come in K or m42 mount--you can use m42 lenses with an adapter. (I've never heard of a Konica in K or m42 mount.)