All I know is Parametric is better for Techno etc, rather than mulit-band (traditional 31-band etc).

Parametric gives a more creative edge I have found and it allows for "sweeping" of freqs to find the best result.

I don't like to recommend brands as it comes down to personal taste which you must decide by listening to it as each unit will add a certain "colour" to the sound (expensive is not always suitable). There is no write or wrong here, just trial and experimentation. Sometimes I use an old crappy 10-band analoge when other times i use PC based parametric.

One thing I have learnt tho is that "Machina" is a bit of a gear nut and he would only recommend good stuff.