I have a Suntek Viper full tower unit from Dabs click here
this only has a 300 watt psu but I have no problems with power. My setup is Abit KT7raid Motherboard 1.2 Athlon (Sometimes overclocked to 1.4) 80GB Maxtor hdd 80GB & 40GB Quantum Fireball hdd, 2CDRW's (1 Plextor 40x12x40 & 1 Generic 24x10x24), Iomega Zip 100,Creative labs sound card and Live! drive, 4usports & pci card with 2 more, 4-80mm case fans a double hard disk fan, MM100PCTV(UK) televison card, Radeon 250 9000pro video card with Samsung 17" flat screen monitor attached, simbios logic scsi card with HP scanjet C5110A flatbed scanner attached. Olypus ES-10 film scanner from parrallel port, Epson photo 895 printer from usb port,pci network card to laptop, usb cable modem usb mouse & serial mouse and a usb game pad. I have considered a larger psu but as I have no problems why waste money. Try out your system of choice before changing psu and see if it can cope.