Stock BOV is at the very top of the image in the middle. Can't miss it. Kind've looks like a duck wearing a trilby. Okay, maybe not, but it is bolted to a section of the crossover pipe (easy enough to remember as it is the intake pipe that crosses-over the engine).
If your car had a BOV fitted to a section of intercooler piping the stock crossover pipe may have been replaced with a new section of pipe that doesnt have the fitting for the stock BOV or in place of the stock BOV they may have simply blocked it off with a piece of metal.
Luckily both the crossover pipe and standard BOV should be easy to find and cheap to buy.
If you insist on an aftermarket BOV, get one that has an rb20det adaptor so it will bolt straight on. Look in the classifieds section as there used to always be ppl selling as-new BOVs for cheap prices as many people get sick of them after a week or two and dump them for peanuts. Also, you can ask them if it makes a PSH noise like you desire or more of a wapachang which it appears you are not.