if you take a look at sean's information, much of what he has tested holds true. there are some performance gains to be had by installing the phenospacer. there are a few 2.0's that have it, including a member of my club who helped sean prototype the item. many of the people who have the phenospacers have them on the 2.5L engines, including myself. i was in on the very first bulk buy, back in the days of the probe-perf list.
the biggest reason why you would want this spacer is to help keep the intake manifold cooler, which will result in denser air and a larger explosion upon combustion.
so, yes he has them available for the 2.0L engine. yes, they do provide some small performance gains. yes, you can get them from the probesport website or directly from sean at outlaw engineering