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I'm extremely confident the cables included in the SF600 will reach the mobo in virtually any mini ITX case, including the TU150. The only reason you'd need extensions is if you prefer different aesthetics. That depends on your definition of "clean build", which is such a subjective thing. Personally I would wait before buying more parts. If you don't like how it looks, order the extensions later. Note, the Platinum version of Corsiar's SF PSUs comes with much nicer cables than the Gold series. I'd definitely recommend spending the extra $20 (US) up-front on the Platinum SF600.