Chase is offering a 30k mile sign up bonus for the UA credit card (after spending $1k in three months) in my experience the miles clear pretty quickly once you hit the minimum spending requirement. Chase also offers other cards that accrue 'Chase Rewards' points that can be transferred one to one into your Mileage Plus account. The current offer looks like 40k Chase Reward miles after spending $4k in 3 months. Upgrading a purchased ticket to the middle east from economy to business is 35k miles and a hefty co-pay. While you could earn enough with the two credit cards to make this happen, the timeline is a little short. Also be aware that you generally need really good credit to qualify for the cards with good sign up bonuses. The following site has a good list of the current credit card sign up bonus offers:

http://millionmilesecrets.com/hot-deals/

UA's upgrade and award ticket rates are here:

http://www.united.com/web/en-US/cont...t-02-01-14.pdf

Good luck!