I looked at Bitstamp but doesn't look like it is a good gateway for me, being in the USA and not wanting to mess with an international wire transfer. Is there another compatible gateway where I can use cash (like Bitinstant) or Paypal or credit card??
You can use BitInstant to send funds to Bitstamp.
How? Got to their website and Bitstamp is not an option to Transfer To. Right now, it only shows MtGox an Bitcoin address.