I am receiving 3 modded original Xbox consoles in a few days. I was curious as to which mods you would recommend hardware wise. also, I am curious here: Is there a mod that causes a "Beep" to sound when you press the power button? Similar to the PS3/360?
Hardware, well an upgraded Hard Disk is about all you need to be honest. Since IDE large capacity Hard Disks are hard to find, any SATA drive will work in XBOX with SATA > IDE adapter/controller board. If you want added functionality like an LCD screen in the faceplate either X3CP faceplate or a custom LCD screen, a modchip needs to have this function like a X3 or SmartXX chip (very hard to find these days). Also 128MB RAM upgrade is possible this depends on motherboard revision. 1.6 is not possible for RAM mod. The POST sounds are made from a speaker, you'd have to make one completely custom for this. Hope that answers your questions