My favorite at night is a safety t-shirt with reflectivity, but don't use one usually because I don't ride much at night in the summer and it doesn't breath like a regular t-shirt. So I usually use a safety-t with no reflectivity and carry a reflective mesh vest in my bag at all times in my bag just in case. You could go a size small to be more aerodynamic. It's just hard sometimes to find actual bicycle jersey that's visible enough for my comfort.