At 6'7, I wouldn't consider inability to do a pull-up or dip a sign of weakness. You're dealing with limb lengths and bodyweights that the average folks aren't. Yeah, there are still some taller and heavier guys out there that are beasts, but I wouldn't sweat it.
Stronglifts and similar programs abbreviated programs are built around peaking strength. Whatever strength you have built up, you will realize it on those programs. They're not bad to run for 2-3 months just to get technique established and a baseline to work with. Once you've done that though, I would advocate moving to a program that is built around building the qualities that create strength (hypertrophy, conditioning, work capacity, etc). Something like 5/3/1, Westside Barbell for Skinny Bastards, Cube Method, Juggernuat Method, Thib's Power Look program, etc. This will be where you really start getting strong.
Alternatively, you could just run those programs now since you have a little experience under your belt. The difference between the two paths won't be terribly significant, it's more about what suits you.