I've recently got some Bulqpak generation 4 dvdrs from
www.bigpockets.co.uk and they work 100% on my version 7, and my dicky version4.
As for suggestions for other media, try these, they all work for me on both my machines (If they work in my v4 then they're pretty much guarenteed in anything!!!)
www.bigpockets.co.uk (as above plus traxdata when in stock)
http://playstationmods.com/cdr.htm#PURPLETOP (Highly recommended)
and anywhere you can find verbatim or panasonic(rf120's)
These are just ones i've tested and find to work. I switch between them depending who has stock
You'l find that your pioneer dvdr will write to near enough ANY dvdr's you throw at it. I've tried some really crap discs on my 104 and it's never not burned correctly. But if it works in a ps2 depends!
Hope this helps,
james