I've just finished a similar build using the Origen AE M10 case with an Intel i3 540 processor.
Couple of points to note, many already identified by other people doing this sort of build:-
- I originally tried using a Gigabyte H55N-USB3 motherboard. When my Origen M10 arrived, it had the PSU with the larger sized capacitors installed, so I could not use this motherboard as the capacitors fouled the ATX socket on the motherboard. Origen have updated the design of the PSU now with smaller capacitors, the model number of the new DC/DC board is PX150-P2. I have one on order from where I bought the case as Origen can supply them to their distributers on request.
- Case Power switch and LED cables must be swapped round when using boards with the Gigabyte layout as the shorter ones will not reach the motherboard connectors. Alternative, buy 2 pin extension leads.
- In the interim I have a Zotac H55ITX-A-E motherboard installed which has a better layout for the Origen M10.
- SATA power cable proved to be too short to reach the Hard Drive when a Graphics Card was installed. I have a Sapphire low profile 5570 1GB installed. I bought a SATA power extension cable to resolve this.
- Stock 60mm case fan is a bit noisey, be careful when ordering replacements, I ordered 2x Fractal Design 60mm Silent Cooling Fans, they didn't fit as the stock fans are only 15mm deep, the Fractals are 25mm. I sourced 2 x Papst 60mm x 15mm fans in the end and fitted them on a fan cable splitter. Much quieter now.
- Stock Intel CPU cooler became noisy under load, there is not a lot of room inside the Origen Case so heat builds up quickly, using the Zotac PWM setting proved too noisy. When I limited the fan to a max speed, temps rose abit too much for my liking. I have now replaced the stock cooler with a Silverstone NT07-1156 Low Profile Cooler. This has a copper core and a switch on the side for Full Speed / Quiet mode. On quite mode the noise and heat is far more acceptable than when using the stock Intel heatsink.
Other than that, am very happy with my build, controlling it with a Logitech DiNovo Mini keyboard. I'm in the process of updating my Logitech Harmony One with new commands to use also.