How to stream video (and process) into FPGA

Thank you very much for all your inputs.

Some clarifications:

• I would like to "play" with some evaluation board. For this project and also for general video processing projects in the future, get familiar with ALTERA product and capabilities.

• I will implement the described project on my own PCB!.
  Eventually it will not stay on the evaluation board.
  That is why i need to understand the flow of bits.
  If needed, i will outsource part of the design but i would really like to get the feeling of things and learn, as you are giving me good information here.
  The 200$ budget i mentioned was for the FPGA alone, i have a camera worth ~600$.

A few more questions:

1. The first challenge is the basics: lets say i choose a camera which has GigE vision interface.

whats the next step? the output stream from the camera needs to be translated into some sort of pixel streaming into the FPGA memory. how is it done? i assume there are modules to be found.

Should i look for GigE to FPGA module? because i didnt find anything i thought was relevant.

2. Same goes for CameraLink which i am now searching for a camera that uses that interface.

3. The second challenge i will be facing is finding a module which can handle the rate i want.

correct me if i am wrong but if i want: 640x512pix, 8 bit, 300fps i am dealing with ~800Mb/s which is high..

where is the bottle neck? the GigE vision protocol? the FPGA i choose? any thing in between? all of the above i guess

p.s. Don't be alarm (talking to my self as well here :) ) i will minimize specifications if i will find the above is not realistic, i just need to understand if it is or isnt and how to figure it out.

4. Do you think the DECA board can handle this? (the low price is making me skeptic...)