Serial Display Daughter Board for 20x4 display

The Modtronix board should work fine on the Arduino. The company is in Australia but they have a US distributor if that is better for you:

I ordered LCD's from 'web4robot' and never received an order confirmation or the product. After waiting a month I disputed the charges with PayPal and eventually received a refund. I'd be surprised if they were still authorized to accept PayPal payments.