Not sure at all about the colour of the blues!!
I would without doubt fit a group a as this benefits even a std cossie, massively.
I would also fit a breather system, would not hurt even on a std one.
Ported head is NOT necessary but when you look at the torque curve of a ported head cos with a non ported, the ported boosts earlier and a lot harder and holds it a lot better, just a very noticable increase per pound spent.
tabetha