A 10X magnifier with a 6" aperture is pretty much impossible with a single element. For any significant magnification, you really want a stereo zoom microscope.
For soldering, you need something like at least 4" (100mm) of "working distance", a bit more is better.
I do lots of precision soldering with an old Olympus, but we have one of the Chinese ones at work. The dual beam stand is good, you want it to be pretty rigid so it doesn't bounce.
Jon