CPLD vs FPGA:

That sounds very much like a job for an FPGA and not a CPLD. I/O count may not be an issue but available logic and RAM resources almost certainly will be.

It all depends what you want to do in 150ns. That could represent A LOT of processing time. I think you're likely to run out of logic in a CPLD, even if you try and do very simple analysis. Plus, the lack of user RAM in the CPLDs means you won't be able to buffer anything like a frame of video which, I assume, is what you're going to want to analyse.