i may not have all your answers...
but here it goes:
the early rotors...forget about it...Dealers want 800 for a set of the floating rotors...these are flat and need to be used with a 25mm spacer if you have the turbo fenders (I know yours is a 930, but I got my knowledge with trying to fit 930 brakes to 911)
without the spacer you can use the full floating on the front of a normal 911
the later style are one piece with no floating hat...instead a integrated hat...with a 21mm (I think) offset. These can be used by the 930 crowd without the 25mm spacer...911 owners cannot used these rotors...boo hoo...unless they have turbo front fenders
You should be able to get the later rotors at dealers or pelican...also check ebay...there is a guy who seems to sell crossdrilled brembos for 911 and 930 all the time...
if you really want to stick with flat rotors what companies have been doing is using coleman, brembo, or generic rotors that are the right thickness and are flat rotors...but the diameter is too big.
So these guys machine the edge of the rotors to make them smaller....these are almost as expensive as the OEM early style rotors....
www.vehiclecraft.com
www.rennsportsystems.com/~porsche
If you do decide to chuck your rotors I would be interested in buying the hats off you...I have some rotors...but no hats...by some rotors I mean one...my search continues.....
if there is a supply problem go right to the source...call stoddard...also Atlanta seems to be one of Porsche's hubs for parts...don't know how to contact them though....