You can choose any case you want but depending on the features then paying the few extra bucks isnt all that bad. Things you should consider is overclocking will heat up your computer so getting a nice airflow through your computer is perfered, atleast 2 holes. 80 fans make a lot of noise, 120 makes less noise, want it quite or loud? mobo tray's are always nice to have. knowing how hot it is in there with gauge or lcd monitors are also very useful. material isnt really much of an issue though, all three are fine, acrylic, steel and aluminum.