<p>Should be available to non-U.S. companies, easy to setup, reliable, cheap, customizable, etc. What are your experiences?</p>

I'd say paypal or
GoogleCheckout
.
Google Checkout is either 2% + .20USD or free depending on how much you spend on adwords. If you spend a dollar on adWords, your next $10 on Google checkout is free.
Paypal
is 1.9% to 2.9% + $0.30 USD (2.9% for up to $30,000/month, 1.9% for more than $100,000/month)
Without factoring in the 20/30 cents, Paypal is just barely cheaper if you sell more than $100,000 per month, and spend nothing on adwords.