Infinity Kappa's all round
I got 6.5" comps up front and a pair of 6"s in the parcel tray.
Not into subs much, i want my bootspace and my hearing in 20 years 
Infinity Kappas usually = 2 ohms impedance, which usually = headunit death.
Had this setup for 6 years now in two mk3s, Headunit is a 10 year old Blaupunkt 'paris' 4x40w.
Does the job well and it can put newer non-sub systems to shame.
Some other speakers i would recommend are Cerwin Vega's