I know you said that you like the upright mirrors. However, you might take a look at the Napoleon bar-end mirrors. They are inexpensive and good quality. I find the visibility better than the stock positions, and they are not an impediment to lane-splitting. Plus, it leaves the holes in perches open for mounting other stuff (I use a RAM ball for phone, gps, etc.) Napoleon also make standard-mount mirrors, but I don't think they make one with the long stem needed for the non-threaded perch.