I see a Dagger Mamba 7.6 for sell locally for $300. From the pics it looks like it’s in very good condition. I’m not sure which generation it is. I don’t think it’s the newest version. Not sure if I can post a link to it here or not? If I can I will and maybe someone else will know which it is. I’m somewhere in the neighborhood of 5’6" and 140lbs.
Dagger Mambas are usually considered to be relatively user-friendly general river running whitewater kayaks. The Mamba 7.6 should be optimal for your weight. If you are comfortable in it, it is probably a good choice.