WHY?!?!?!?
1. Please take our advice, or at least seriously consider our suggestions before you pull the trigger on anything and possibly make another mistake. I'm not trying to be mean; I'm really just trying to help. Several people advised you not to apply for the CSR because Chase's new rules meant you won't get approved for the card or you won't be eligible for the bonus. Several people then told you to wait to apply for the CIP because Chase's rules for business cards require you to have no other application in the last 30 days. You ignored all our sound advice, and now you're talking about applying for the United MileagePlus Explorer Visa (not MasterCard).
2. Please note that the United MPE Visa currently has a public signup bonus offer of only 40k MileagePlus miles. The public offer was 50k miles about two months ago, and people were being targeted with 70k miles offers then. The MPE has a 60k targeted offer right now. If you haven't been targeted for the higher 60k offer, there are numerous tricks to get yourself targeted for the better offer. But if you rushed carelessly into another application, you might have settled for the lower 40k offer without even knowing it.
But like
@calypso726 said, you're going to have to wait to apply for the United MPE because you've already submitted two applications in the last 30 days. 30 DAYS! Please take this time to read up, ask questions, take advice, explore different credit cards and rewards programs, flights and prices, learn the rules for approval from the different banks, and formulate a strategy that works for you.