I would agree w/ woodfloorist, and not surprised that you are getting conflicting opinions. His points are right on.
Regarding teak, yes, does tend to gap more than the others, and if you go 3 1/4" plank vs. 5", that will help. And, yes, it's more challenging to refinish than oak. And, it's more challenging to cut and install. (BTW, you could also try Braziian Walnut which is similar/has similar characteristics, but a bit darker and less gapping).
Handscraped or distressed is a stylized and taste specific choice, so only you can make that choice - you like it or don't. But, do consider how long you will be there and when you would resell as this might limit the interest in your home. This might also depend on geography. Here in NY area, most people do not like this look.
Solid oak is always a great choice and it can be refinished - either by you or next owner and the colors changed easily so it's widely appealing and practical. It also tends to show scratches less than teak.
Regardless, I would look into your subfloor. OSB is not a great base. I would recommend 3/4" plywood instead, regardless of which hardwood you install.
Debbie Gartner aka The Flooring Girl
http://TheFlooringGirl.comWestchester, NY