The Decware switch in a box looks really good.

Niles makes some switches for about $75.00 each

This is just a pushbutton A & B switch

Here is a five input selector
The DIY switches discussed, the DACT and Seiden are both 5 position.
The Grayhill

and Elma

can be obtained in 2 position or more.
I have not listened to any of these switches in comparison to any other. I think the Decware would use better parts than the Niles, offhand.
I would suggest that one as possibly the more transparent of the built in a box switches