Anybody specialize in heads up?

So, I'm still in that ugly phase where I'm playing freerolls to try to fund my starting bankroll. I have a heavy interest in pursuing poker, but finances at the moment don't allow me to fund my bankroll directly. Unfortunately, I think I'm coming to discover that I generally play my best poker when the table is short handed. Either heads up, or a threehanded format like spin & go's. *haven't played any spin & go's yet, but I've played a good amount of three handed tables with play money*. Somehow I just feel more confident in my decisions, and have a general tendency to come out on top more often than not. I have a feeling that when I finally break my freeroll barrier, that will probably be the type of game I attempt to specialize in. I've come across a good amount of information on short-handed strategy, but I was wondering if there are any specific books or articles people would recommend that might contain a few hidden gems, or maybe as a good source of strategy that might go against the common wisdom *Yes, I know common wisdom is common for a reason. lol. I'd simply like to open up my perspectives on the issue, see if maybe there are any theories or ideas I can incorporate into my own strategy.*

Also, in a more philosophical sense, has anybody out there had any luck moving up the chain in any of the short handed formats? Would love to share opinions or experiences, having a support group of more experienced players would be nice when I get the chance to start trying my own climb.

I'm not a specialist but I believe J7 suited is the average heads up hand. So if I'm small blind, I bet 3x the BB with J7 suited or better. That means Q6 suited, K5 suited, and ANY ace. Now, if I have J7 suited and someone bets into me then I have to read the situation a little more in depth.