Uh... are you, perchance, looking at those 3 or so ridiculous people on ebay selling them for 350 a pop? Or are you more into the building the pickup part than the actual owning/using it?
Cuz, otherwise, you can get CERTAINLY get Maxon/Ibanez Super 70s, the real deal from the actual 70s, for probably less than the new SDs you were considering modding.
The trick to procuring Super 70s is to buy them with the guitar. Which, then, you can sell at a premium with the above-mentioned Duncans as a "premium upgrade".
The secret? Despite the advertising, Super 70s were NOT unique to Ibanez guits, not by a long shot. Early 70s Grecos, Westminsters, and over9000 other Matsumoku builds had them standard.
Ex: 1972 Westminster (MIJ Matsumoku, certainly not Ibanez, although an identical product was simultaneously sold with Ibanez on the headstock... as well as another one that said Greco,
Also, another trick is to look for the stranger designs, especially the open coils with the unusual brass (?) rim sealing it up and PAINTED black to look like plastic
I've gotten a pair for $125, with an awesome LP and a hardshell case to boot (see above). Not that they're leaving that beast. Super 70s pair NICE with maple fretboards... and, hey, zebras? HAWT.