If you really want a Celeron, I'd say get an Asus CUBX motherboard, get a Celeron 533A or 566 and try for overclocking. But I think you should really consider the Duron if you are into Budget, unless you want really low end and you go i810E (integrated graphics and sound).
If you want a good performing system without costing you to much, you should definately go Duron, it performs much much better than the celeron.