replace mega16U2 on Mega2560

like I said, I've got a parallel programmer, so I can program the chip through the ICSP header next to it, and no, I don't have any other of these "pocket programmers" that you speak of, nor do I have another arduino. I'm thinking I need to find a different solution though cause Atmel refuses to send samples to anyone using anything other than a business email, maybe I can get a chip from Microchip or something, anyone have some recommendations on chips that are good for serial to USB?