To me there was not enough difference between the 314-Ce and the 414-CE to justify the difference in price. I bought the 314 and never looked back. My personal opinion was that until you got up to the 714 and higher range, the difference in quality wasn't substantial. I have really enjoyed my Taylor.
As for the credit card...just be careful. Credit can be a great thing, and is very necessary to having the nicer things in life, but keep your credit GOOD. Take advantage of the no payments/interest thing until 2008 by MAKING PAYMENTS every month...right away. Even if it's $100. What they put in small print is that if the balance isn't paid of by December 21, 2007, interest is retroactive to the beginning of the account. Make sure it's paid off by then, and you've just used someone elses $$ for 1 year to pay for your gear. If you don't, that $2000 guitar just cost you $3000 and your good credit for the next 7 years.