I am using paypal and
www.propay.com myself. I have very few clients that use paypal, but you're client doesn't have to have a paypal account. My 1st choice with my clients is propay.com a friend of mine uses the service and it works for me.
My suggestion is to look at both and may search for a third and compare prices. You are going to have to pay a fee, you jet need to figure how how much you can afford.
Don't get a credit card machine, i had two and the fees are not worth it. So if you can do paypal or propay ($starting yearly fee is $59. I would choose one of those.
Good luck
Julian