Regarding selection of appropriate board for application development

I agree with thepancake..

It really depends on your requirements and company preferences.

Are you expecting to use the Arm9 processor? If so, realize that neither the Zync or Cyclone/Arria SOC devices have a hard video interface. This is both good and bad. Good is, you can get softcores or design your own if it's your goal, Bad: It takes up lots of FPGA fabric to do video the basic video processing..

One good method is if you have an external processor that has the basic video processing engines, then you make the device a PCIe device, and pass the video back and forth this way.

The Next question is how big and how fast must your logic run. The like pancake said the Zynq and Cyclone5 SOC/Arria SOC are midrange devices. They have dual 800+ MHz A9's but the fpga fabric is not as fast as the Stratix V. The Stratix V also can provide many more gates than the current generation of SOC based FPGA's.

Having done video engines in both Altera and Xilinx families, it can be done in either, but your requirements really push the final decision. If any of the above will work for you then the end of the day conclusion, may be who do you think you can get the best support from.

My personal experience has been I get the best support from Altera, but I know larger Tier 1 customers I deal with have in the past said they get better support from Xilinx. Of course a lot of this has to do with how big of an account your are. Altera seems to help the little guys out better. Where Xilinx focuses it support on the Tier 1 guys.

Pete