Thanks for the question.
You're in good shape either way you wish to do this. You appear very responsible and don't seem to be the type of person who overspends with credit cards and gets into financial trouble.
That being said, you should put the HDTV on the credit card with the lowest interest rate. The card with the 9% rate is a good rate and probably the card you should make the purchase with unless the higher limit card has a better rate.
I hope this helps - Good Luck !
Financial Advisor
15 years expertise in all ares of personal finance, including credit cards, mortgages, real estate.