@TheMagicM
use a Radeon9250SE or a Radeon7000. These are low profile and fit without problems. Remember to use a low profile AGP card or your ATX power connector may be covered by the AGP card (not a good idea probably).
There are also Radeon7500 low profile and Radeon9100 low profile (although these low profile R9100 are very hard to find)
