Gotta admit, I'm a bit derelict with the P-Funk in my music collection.
Slam, IMO, has broken it all down correctly.
I picked up Funkadelic's DEBUT album today(
Funkadelic)...almost 'Hendrix-like'.

Next, I'm gonna pick up Parliament's
Funkentelechy vs. The Placebo System...horn-driven Funk.
BTW, a very, very cool site to browse & pick up some of this stuff-
www.dustygrooves.com
...I just ordered an album from them called East Bay Rhythm(Paul Jackson on bass, Bill Summers on percussion...supposedly, very Headhunter-esque. We'll see).
The site also has some obscure & hard-to-find Jazz cds & LPs(I've been searching high & low for Jackie McLean's
One Step Beyond & Gil Evans'
Into The Hot...they actually have both IN-STOCK!).