DescentBB

I'm currently on a highly used Dell QuietKey keyboard. I have a problem though. It won't let me press 4 keys at once, unlike some other keyboard I've seen. I'd like a quiet keyboard(if possible, doesn't have to be though) with just the windows key between the left Ctrl and the left Alt key AND that will let me press Ctrl/Alt mixed with Caps Lock/Shift mixed with A/S/Z mixed with the spacebar I have a demanding D3 config

Are there any programmable keyboards around?