I have to agree with Zona. Save your money longer instead of spending what you have on either of those. Try to keep your emotions in check and just watch for a used one to come up close enough for you to test ride. Be sure to test ride a 700c bike, 26" wheel bike, touring bike, etc. Try to adopt the mindset of knowing it could be a couple seasons until the right tandem comes around that's the perfect size, and close enough to ride, and that you know is right after riding. This is assuming that I'm understanding your post correctly that you already have an older tandem.