The old Antec Performance SX / Chenming Dragon series of cases are solid, but their reliance on 80mm cooling fans makes them noisier than newer designs using 120mm fans.
Unfortunately, the old 400-watt Antec PSU (e.g.: PP-403X) cannot provide enough current on the +12V line to power modern systems. Much of its total capacity is on the little-used +3.3V and +5.0V rails. A measly 12A of +12V is only 144 watts on the rail from which modern PCs draw most of their power.
You could re-use the case, but the PSU will have to go.
I'm moving this thread into the Case and Power Supply forum.
i7-6700K, NT06-Pro, GA-Z170N-Gaming5, 32 GiB, 980Ti, SM951, 5TB HDD, Blu-ray, FTZ01, SX600-G, 3007WFP+2001FP, RK-9000BR, MX518