If you've got a 4-blade neg mask, then the 6x9 glass neg carrier should be fine. There's no real need to use a dedicated 35mm neg carrier.
Since enlarging lenses are cheap these days, you might want to upgrade to 6-element lenses for 6x9 and 35mm (like Componon-S or Rodagon), but unless you can't make big enough enlargements from 35mm with the 105mm lens you have, there's no rush.
Another reason to use a 50mm lens with 35mm is that you won't have to raise the head as high, and that can reduce the effect of enlarger vibration, but unless that's a noticable problem, use what you've got for now, until you find a better lens.