shimano 600 is also ultegra, the names were combined at somepoint then after awhile the "600" was dropped. it's second from the top in the groupset hierarchy from shimano, the 8speed version is pretty much period correct for the frame, wheel wise again the ultegra hubs with mavic rims, open 4cd would be my choice but maybe cxp22's, if not maybe a set of mavic wheels.
@gillepy, haven't seen your thread.