Option 5 is the least appealing to me as it really does look like an app button like someone mentioned. 4 definitely seems the most "professional". I kind of like the first color scheme in 6, but it just seems to be a bit "too busy" for me. I like the font in option 2, but the logo seems a bit too much. Option 1 doesn't make it look like a coin logo.
Here's a larger version of option #4 for consideration:
