Need help replacing a PSU

[Orrhias]

I'm ready to buy a case for my DIY router. Settled on Apex DM-317-A, but don't like the included PSU, so need to replace it. Was going with the Corsair SF Series SF450, but some on other forums said its too big for the case (I had thought SFX was smaller than TFX), so need suggestions for a TFX PSU. Around 400watt. Must have mostly good buyer reviews (50/50 reviews like the Pico line is not good enough). Thanks.