Honestly, I'd just up the weight on barbell rows, high pulls, dumbbell rows, etc.... and keep practicing trying to get a real chin/pull-up till it happens.
I look at all the old lifters from the golden age of the sport(pl/ol) that where able to chin their asses off, and it's sad that today's lifters have to resort to such things as "fat man pull-ups".
If you have any sort of pulling power, you should be able to at-least knock out a set of body weight pull-ups.
No offense to the original poster, just some thoughts:).