PhilMurray - you can play copied games without a modchip on PAL/US/JAP xbox's by soft modding. it uses a save game exploit to launch a Linux based aplication on your xbox
soft mod tutorial I personaly wouldnt suggest doing this if you are a noob to soft modding, it can ruin your xbox.
Back to xbox drives and media.. No matter what drive you get it may or may not play certain media, its all luck of the draw. You can have 2 xbox's with the same drive and one will play (for example) memorex dvd-r's and the other wont. What it comes down to is no matter what drive you get you will still need to find the media that works with it so dont stress on the type of drive you have or will get.