If I were you, I'd ditch the choke chain.
It really depends on the dog, but I've used a prong collar on my dog and it worked like a charm. Just make sure it's properly fitted.
Other members of this forum have used Gentle Leaders and gotten good results, so that could also be a viable option.
If you're trying to discourage pulling, don't get a harness. There's a reason harnesses are used on sled dogs and weight pull dogs. A harness actually encourages pulling.
"When we speak of bulldogs, the words that fit, Are those like courage, stamina and grit."-Floyd Boudreaux
"How many times have we heard the phrase 'I felt so Good I could lick the world!' Well, the American Pit Bull Terrier feels like that all the time!" - Richard F. Stratton