For the case, any standard atx case will work. I've used antec, rosewill (newegg.com) and enermax. All work fine. For the motherboard, your dell has the nvidia 6100 and 430 video. I use the 6150 which is newer and works with all am3 cpus up to 95 watts. If you have ram slower than 533 ddr2, you may want to switch to a ddr3 board and ram. If you don't want to reinstall all your software, it's worth a shot to use a 6100 or 6150 motherboard just for this reason. If you want more features, go with a 790 or 785 chipset board.