Welcome welcome, what kind of system spec's did you go with?
I had originally spec'd a Xeon based system with the Supermicro X10SL7-F Mobo but I couldn't find a case small enough to handle 6 HDDs in that (mATX) form factor whilst fitting into the cupboard I had earmarked for it. So, I switched to a mini-ITX system, so really the only differences from the original spec were the Mobo (and CPU, obviously) and case.
My setup is:
Asrock C2750D4i motherboard with Intel Avoton C2750 8-core CPU
32GB (4x8GB) Crucial ECC RAM (2x CT2KIT102472BD160B packs)
6 x WD RED 3TB HDDs for storage
2 x Sandisk Cruzer fit 16GB USB thumb drives (mirrored) for the OS. It's quite difficult to source SATA DOMs in the UK unfortunately, so I went with USB drives
Seasonic G450 modular PSU. I had originally got the G360 but swapped it out after realising it didn't have enough SATA cables for the HDDs
Fractal design node 304 case
I'm just waiting on a USB3.0 to USB2.0 header adapter to complete the hardware but I can progress the memory and HDD tests without that. I was originally a little concerned the PSU might be out of it's optimum efficiency range with the Avoton rather than the Xeon but I'll live with it unless I'm warned otherwise. In an ideal world I'd be running the Xeon (E3 1231 v3) instead of the Avoton but I wasn't prepared to have the box sited elsewhere in the house so dimensions won the day.
Thanks for the replies so far ;)