Either way is fine, i feel the opposite of you actually, that the peak performance lugs are the expensive but quick option and the s14/300z part usage route is the cheap but time intensive route.
Honestly though, going 5 lug is fairly pointless on 240sxes. If you're doing it for a brake swap, just get your rotors redrilled to 4x114.3. If you're trying to get wider wheels, look at FNs, played out as they may be, or Gram Lights. Both of these are handsome wheels and can be had on the cheap. Also visit
http://www.takumiproject.com and the sponsors for other alternatives.
Save your money and spend it on things that will make your car go and stop faster.