Yup, CSO's and Specials are different.
Not sure whether they are Specials or not. In some forces the Specials wear exactly the same uniform as a regular officer, some have only subtle differences (like 4 digit PC numbers instead of the 3 digits that the regulars have).
Other forces treat their specials completely different to the regulars, making them wear quite visible identifying uniform, like different badges, epaulettes, etc.
It's gotten alot better in recent years though, more and more forces are removing the disginguishing features from specials, as they can attract antagonism from the lower ends of the gene pool...."You can't arrest me, you're just a special, blah blah" (How little they know...lol)
As for the height restriction, that was removed a number of years ago now.