Better, more expensive equipment doesn't actually make you a better photographer. It takes limits out of your way, true. But sometimes limits are good things. You have to think of a way around them, or a way to use them. Fighting against a limit can teach you a lot about technique. My el-cheapo 75-300 III taught me more about how to properly use a telephoto lens than any other lens I own. Not to mention, you've already discovered the joys of adapting manual focus lenses on the cheap.
As for cheap flash units, have you considered going Nissin or
Yong-Nuo? Those seem to be the frontrunners in the Strobist discussion threads of cheaper ttl-capable flashes in the $80-$200 price range. Or, if you want manual-only, there's the
LumoPro 160. Assuming you don't hunt up a killer deal on, say, a used SB-24.
