Credit card suggestion for large US purchase?

I need to spend $3,000 USD at the end of this month. Looking for a credit card that's good for this purpose. I prefer straight cash back or welcome bonus.

Apologies in advance for asking this. I tried looking through the threads but they're all very long.

I think the best option is the Amex SimplyCash with 2.5% foreign transaction fee, 10% cash back up to $400 cash back? greatcanadianrebates has $40 rebate on it as well.

Cards I already have:

• Rogers world elite
• Tangerine MC
• Canadian Tire world elite

I'm familiar with the churn game and don't mind a bit of hassle to save a few hundred bucks.

Thanks!