The most important measure of "good" is how intuitive the program is to you. If you have to fight the program to make something, it will never be "goo...

Open the rar archive file in something like blender or tinkercad. Export as stl. Open stl in your slicer.

For best Cad Experience go with 6 cores like 8700k. and for 8 cores, 9700k.