No, they don't suck.
Alright, the last two camera links you posted are the DSLR's you hear everyone talking about. What a DSLR means in techy speak is "Digital, Single Lens Reflex." In regular speak, they have lenses you can change, and an optical viewfinder that actually looks through the lens you are using to take the picture. When you push the shoot button (no, this is not what it's really called), a mirror flips out of the way behind the lens, and the sensor gets exposed, and the mirror flips back down. DSLR's actually have a click you can hear when you take the picture.
Advantages are many, along with some disadvantages (size and weight). In the long run, the biggest advantage is you can upgrade a DSLR with lenses, external flashes, and all sorts of other goodies. Point and shoots, you generally can't.
I hope this cleared up some of your questions.
Both of those DSLR's you linked to have newer (but more expensive) versions, but they're still great cameras, especially for the money.

I'm not going to get into the differences. I'll let someone else do that, or you can PM me. I've got plenty of time to go into specifics, and am patient enough to do so.
Either way, good luck in your search. You've come to the right place here at TPF!