I understand that you are a beginner - but did you even look at the DB9 serial port version of the Arduino schematic - you would've seen a few components sitting between it and the ATMega (which act as a simple buffer/level translation)?
Also - did you not review voltage levels of the ATMega for the RX/TX pins and the voltage levels of standard RS-232?
I only ask this because ultimately, as a beginner, it is important that you do "RTFM" - when it comes to electronics and electrical work; research everything, review what you are going to do, and check it again before you do it; its that whole "measure twice, cut once" philosophy.
Doing this in the future will save you time, money, and potentially your life. Don't disregard this advice, please!
Regarding the question of the FTDI chipset; I am not sure if a thru-hole version is available, but I doubt it. You can, instead, solder the needed pins to a header (check out an RBBB - Really Bare Bones Board - schematic), and then use an FTDI cable instead, to get around the need to solder the SMT chip.
There's also breakout boards like this one from SparkFun:
Good luck with your future experimentation!
