Answer: There have been good suggestions, the Slingshot being (at least in my experience) probably the best. Only thing that kind of sucks is getting that thing on my forearms; it takes forever to get on sometimes. Maybe I have huge forearms? I don't know. HOWEVER, don't get too wrapped up in doing dips just to do dips - meaning there are a ton of great movements out there you can use for assistance work and still be awesome; close grip bench, football bar bench press, any dumbbell pressing movements (flat, incline, standing), triceps pushdowns/extensions, push-ups.
And I know you are being facetious and self-deprecating but be wary about your internal voice i.e calling yourself a fatass. We here, on the Jim Wendler forum, are really only concerned about your putting your best foot forward and kicking ass. And I should point out that your "best foot forward" is not "giving it the old college try". I believe we all deserve better effort than "working pretty hard" in whatever we are doing. Give more of yourself to less things - things that actually matter.
I have said this numerous times to people but from a dude's point of view, I'd rather have a "normal" or "chubby" girl that works hard, is smart and funny and trains balls out...and lives and really loves life rather than someone that is so damn caught up in diet, their bodyweight and is all consumed with appearance. Having pride in your appearance is admirable but no one wants to hear about your stupid diet, your meal prep, your workouts or smell your whey protein farts. If you've never been out to eat with these mongoloids, here's what you can look forward to:
"Is there gluten in that?"
"I'd like the Surf and Turf but no lobster. Or steak. Or any of the sides you have available. Just a boiled chicken breast and something green."
"Is the pubic hair in my soup organic?"
And with women that really matter (the ones that you actually want to spend quality time with) - they think the same way about dudes.