if your bike shop will cut and sell you spokes, they should be able to tell you the length you need. spocalc is not, in my experience, as accurate as it could be - i strolled into a shop saying, "spocalc told me i'd need 297mm spokes for this wheel," and the guy thought for a moment (yeah, thought. not consulted anything till later) and said, "nope. 290."

anyway, go to your shop and say, "i want [blah blah blah] rims, and i'll be getting miche hubs. X number of holes, laced X-cross. how long are the spokes i need, and can i buy em from you?"