There are many good ones. I try to make moderately priced kits but there are many more expensive ones that are certainly good too.
Personal favorites / good quality experiences.
Zen - magnetic cap
Magnetic vertex
Jr gent 2 (the artisan series)
Atrax
Virage rollerball
Rhinehart
Sedona
Desire and eagle stainless from lazerlinez.
Higher priced - jr statesman, jr majestic, triton...
If I had to choose only two to make it would be the jr gent 2 and the zen magnetic cap which is only a roller no fountain.