Not in the long run and not in your situation. If you're organized, have great score, keep track of your cards, do not go into debt or late payments, then you stand a very good chance never have to pay for your travel ever again.

There is only one major condition though. You must be willing to do your homework and start studying this thread. It has everything you want.

You need to concentrate on sign up bonuses rather than regular cahsback. Which is easier: to apply for a card and get 50,000 miles or to spend $50,000 and get 50,000 miles? Just think about it!

Anyway, back to your question. I don't recommend dealing with Delta at all, at this point. I know it's convenient for your hometown, but Delta is a pain for accruing and for redeeming miles.

Citi AA currently has a personal and business credit card with 50,000 mile sign up for each. You and wife can easily get 200,000 miles fast. That's 4-5 Roundtrips to Europe in coach or 2 in First/Business. Read the relevant thread: http://www.flyertalk.com/forum/credi...ost-first.html (Wiki and the last 10-15 pages).

Yes, you absolutely can apply for a business card even if you don't have a business.

Chase United has 55,000 bonus but there is a trick that need to be employed. I wouldn't start there.

Chase Sapphire Preferred has 40,000 point bonus, and their points can be transferred to United and other airlines. Chase also has two separate business cards, Ink Bold and Ink Plus with 50,000 point bonus each. It's easy to collect 280,000 Ultimate Reward points between the two of you in a short period of time if you don't mind high spend requirements. An RT flight to Europe will cost you 60,000 miles on United. Find discussions about Chase Ultimate Reward cards here: http://www.flyertalk.com/forum/chase...e-rewards-722/

All this stuff will make your head spin at the beginning, so you'll have to decide if you're willing to learn and change your paying and charging habits. Because habits, as everyone knows, die really, really, hard.

Good luck, and welcome to Flyertalk.