Which Microcontrollers work with UNO Rev 3

I just purchased some Arduino UNO Rev 3 controllers and I am fairly new to this. I got the version with the ATMEGA328P chips and was going to order some spare chips in case I fry a few while learning. I don't have the units yet as they are ordered and in the mail. I see they make a bunch of different options with the ATMEGA328P chips. Like one that is a ATMEGA328P-PU and I am wondering if I need to buy just the one with the "P" or will the one with the added "PU" also work.
Thanks

if you "fry" the processor, you'll might also have fried other things on the board (like damage the trace due to over-current) of your arduino UNO...

to your question ATMEGA328P (P is for Picopower) is the denomination, what's after the dash relates to packaging and/or Operational Range of the chip. PU means it's a (Industrial) -40°C to +85°C 28 pin DIP chip

you'll find details in Microchip Technolog's Data Sheet

Both will work.

Thank you for the detailed reply. I think I am smart enough not to fry the traces but who knows. I just read on the Arduino website or somewhere that they sell the UNO that if you make some mistakes while learning you can likely just spend a few dollars and replace the processor.
Thanks again,
schemer

I deleted that post by accident as I was going to quote your reply.
Thanks for the info,
schemer

yeah I've a few set aside that I never ever used... I don't think I ever killed an Arduino Uno.