The dual-capable Tualatins are the ones with 512kb L2. Not cheap

but powerful. For what it's worth, a dual-1200 Celeron system would not be much different from a single-1200 Celeron system unless you have multithreaded apps (plus a dual-aware OS such as WinXP Pro, Win2000 or WinNT), or unless you routinely bog the system down with long ongoing tasks and could use the second CPU for word processing/browsing/whatever in the meantime.