I'm 6'-1"
Standing workbench = 39"
I guess it depends on what kind of work OP expects to do while standing. I don't think most people solder while standing at their bench.
I'm 6'0, and I would not like to do any soldering at my 42" bench while standing. It would be rather low. I would have to lean over on my elbows to see anything. OTOH, it's a little high for using a plane. So it just depends.
My main bench comes to my wrist when standing, to 36". It's slightly high when sitting, maybe two inches, because I like to stand to do other things. But I use a microscope or magnifying lamp while sitting in a regular office chair to solder, no problem. If my standing bench were that tall, respectively, it would be over 50" high. Sub 2", and 48" would be fairly ideal for soldering to me.
I think ideally, you will probably want to be sitting when soldering, because you don't want your bench to be that tall where you can't even use the back of it or reach across it to your test equipment.