C'mon. Just train and lose fat, it will happen. When I lost 50 pounds in boot camp and dropped to a seriously unhealthy 135 at 5'8" I could do over 50 pullups nonstop without breaking a sweat, serious. 6 years later I'm at 200 pounds and can do around 25+ pullups in a row. Gain the muscle, then lose the fat and amaze yourself with what your new body can do. I'm positive that if I dropped to 175 now I could do around 50 pullups. Pullups and abs on a skinny dude is like a fat bitch with tits, not impressive at all.