But good buoyancy is good buoyancy in any gear, and good trim is good trim, and I'll bet JJ could trim out in a poodle jacket if he had to dive one.
I agree that good divers can make any equipment work. (And some new divers are just naturally much better than others.) It is why it is very difficult to get very experienced divers to see that there are better ways to dive than the abominations many of them have adapted. But, the right equipment is easier for all divers, particularly newer ones.
While I have seen JJ do some pretty amazing things, if he can use a cloth second stage regulator cover as a BC, I will eat my shoe.
Now, if the original poster wants to switch to a 5' hose first, I really don't care. (Mistake, he should use a 7' if his diving budget is this restricted.) But, asking the question that was asked as it pertains to DIR is about as relevant as someone asking if it is okay to just use one pink jet fin since they are still in the closet.
What the OP needs to do if he is interested in DIR is to perfect the basic skills. The best way to learn to do that should be an open water class. But, 99% of the time, that doesn't work out. So, the safe bet is a fundamentals class. And, barring that, getting out and learning for himself good buoyancy (and yes, I rarely spell that correctly) skills. DIR Atlanta's advice, while not the fully formed advice you would get from say a fundamentals class, was correct in terms of directly answering the original posters question of whether or not to get a BP first. To better practice his buoyancy, he would be better off with a BP. But, since this is the internet and you can't learn to dive here, that advice isn't the whole piece of the picture as I pointed out earlier.