what type of purchase? You are most likely only going to get 1% if it is electronics or other major purchases. you will usually, only get 5% of gas and groceries. Are you only wanting cash back, or are you will to take reward points?
If you only want cash back, I would do this....
Get the Capital one no hassle cash card... make your purchase and get your 1% cash back.
Open the Discover card and transfer the balance. They have 0% APR on purchases and transfers for 1 year.
By doing this, you will get the most cash back and not have a high APR fee for 1 year.
If you are wanting rewards...
Get the chase free rewards cards. This CC gives you 1 point for each dollar you spend. Additionally, they have 12 month's 0% APR.
After the 12 month's 0% APR is up, look around and find the best rewards card that also has a low APR %
If you have really good credit, you can switch cards on a yearly basis and never pay interest. I have been doing this for 3 years, because of major purchases we made. As long as your credit is good, opening and closing CC's will not impact you.