Ducker, I understand where your coming from and Jim is just trying to save you heartache down the road.. when you realize that the frame is junk. That being said, you can still do exactly what you wanted but I would keep a couple things in mind, will that fork you want work in a better/newer bike more like you want when the time comes? The answer is probably no since your current is a hybrid.. seatposts are a lot more universal so almost no worries there. Now keep in mind your derailers are paired with your shifters, they're intended for each other and your cogs and crankset, now I could be wrong about this part but the hybrids I've seen tend to have mountain bike components and I have heard of people using those parts to setup touring bikes but it doesn't seem to be common I'd even go as far as going against it since your budget seems limited and probably your wrenching experience, so tell me though why do you want to upgrade a derailer? or both? or what? But considering you could probably buy a nice vintage road bike for 100 in decent shape (probably not high end) but much better suited for roads then a hybrid.. hopefully I've given you some info you can use.