The front 914/6 rotors are vented, basically the same as an SC (A caliper) rotor. The stock 914/4 calipers won't work as-is. I think I heard someone say you can split the caliper and insert a spacer between the halfs to use the vented rotor, but I may have that completely mixed up. (Odds are good).
The rear /6 rotors are available and the best way to go in back. Really no point in re-drilling rear /4 rotors. You can keep the stock calipers in back.
AFAIK Pelican doesn't offer 5-lug conversion parts (I could be wrong). GPR sells ready-to-go kits with new studded rotors and bearings but they are fairly spendy. FAT in Orange County also says (in their catalog) that they can drill rear hubs on an exchange basis.