Check the UA FAQ and Wiki - there's a Chase Visa card that comes with up to 15k EQM - and I think 5k of those are sign-up bonus.

It's not a cheap card - it's $140 - but it'll save you a good part of a weekend, and that's worth a lot more than $140.

Of course, that Seatte fare for $220 is very good - and this is the perfect time of year to spend a couple days out there. If you can get that fare, I'd do it whether you need all those miles or not! ^