ok heres the story. i have a stock 98 gtp with a 122,000 miles on it. when i drive my car normal it drives normal most of the time but it does act up too. when it starts to act up it hesitates to shift and when it does shift it shifts abnormally hard. if im going at a slow roll and stomp the gas when it shifts down its almost like its wheel hopping but it isnt the trans is shaking really hard. this even happens at high rolls but not all the time. i took it to a place and the guy says it sounds like its the torque converter. i just want to get some more opinions before i start buying parts.

can you guys tell me what trans part number i have in my car?
also can you supply some web sites where i can buy some OEM replacement parts for my car? i need motor and tranny mounts, converter. as of right now this is all i think i might need.

thanks for all the help