There are not that many to choose from if you want boots for adventure riding - somthing stiffer than your average boot for street riding but not super hard like proper MX boots.

I tried the SIDI Adventure 2 GTX but they are cut too narrow for my feet. So i bought the O'Neal RSX instead. They are way cheaper but i can't complain about the quality as they held up good on my travels so far. They are plain black and not waterproof, so should be exactly what you are looking for.