ATMEGA16U2-MU UsbToSerial Proteus Development Project

HI,

I'am a newbie in arduino and micro controllers however i'm trying design my own arduino board in Proteus, now i'm stuck in ATMEGA16U2-MU because Proteus don't have this component in the library, but have the AT90USB646 I try connect the wires and use the same firmware used on 16U2 on arduino IDE directory but not work.
I try user other firmwares USB-to-serial but and nothing.

I need help with USB-to-serial!!!!!
I'm completely lost!!!

Thanks!!!

ATMEGA8U2-MU ??
FT232RL ??

Thanks for fast reply,

Unfortunately don't have that one too, I have a list from Proteus website maybe help (see on bottom of the page)

http://www.labcenter.com/products/vsm/avr.cfm

[b]AT90USB646[/b], AT90USB1286
ATMEGA169, ATMEGA19P, ATMEGA329, ATMEGA3290 (LCD AVR's)
ATMEGA329P, ATMEGA3290P, ATMEGA649, ATMEGA6490 (LCD AVR's)
ATMEGA640, ATMEGA644, ATMEGA644P, ATMEGA645, ATMEGA162, ATMEGA165
ATMEGA165P, ATMEGA325, ATMEGA325P, ATMEGA3250, ATMEGA3250P, ATMEGA2313
ATMEGA8515, ATMEGA8535, ATMEGA1284P, ATMEGA8, ATMEGA8(32PIN), ATMEGA16
ATMEGA32, ATMEGA48, ATMEGA48P, ATMEGA48P(32PIN), ATMEGA48(32PIN)
ATMEGA64, ATMEGA88, ATMEGA88P, ATMEGA88P(32PIN, ATMEGA88(32PIN)
ATMEGA128, ATMEGA164PATMEGA168, ATMEGA168P, ATMEGA328P, ATMEGA328P
ATMEGA168P(32PIN), ATMEGA168(32PIN), ATMEGA324P, ATMEGA1280, ATMEGA1281
ATMEGA2560, ATMEGA2561, ATMEGA6450, ATMEGA103, ATTINY10, ATTINY11
ATTINY12, ATTINY13, ATTINY15ATTINY24, ATTINY25, ATTINY44, ATTINY45
ATTINY48, ATTINY48(32PIN)ATTINY84, ATTINY85, ATTINY88, ATTINY88 (32PIN)
ATTINY261, ATTINY461ATTINY861, ATTINY2313, AT90S1200, AT90S2313
AT90S2323, AT90S2333, AT90S2343, AT90S4433, AT90S4434, AT90S8515, AT90S8535

I'm very desappointed with Proteus, have a great VMS but the library sucks

One more time thanks for fast Reply
Regards