<< chase debit card with United Miles.>>

I understand you mean the Mileage Plus Visa Check Card which earns 0.5 miles per dollar (1 mile for two dollars). Is that correct? It appears that mileage is capped at 60,000 per year unless you are a United Mileage Plus Premier®, Premier Executive®, Premier Executive 1K® member.

Inasmuch as you are in Dallas you might prefer the corresponding AAdvantage debit card issue by Citibank. "If you elect to enroll in the Premium Citibank® / AAdvantage® Debit Card you'll get 4,000 bonus miles, earn 1 AAdvantage mile for every $1 you spend on signature-based transactions and pay a $65 annual fee." However, this is capped at 100,000 miles per year with no apparent waiver for elite members. (Bear in mind that all AAdvantage miles count toward lifetime Gold or Platinum status.)

Do you have to use one account for all the purchases? One strategy would be to put as much as possible on a mileage earning credit card and the excess on a debit card. Over time the payment history would probably lead to an increased credit limit.

dennis