Below is the parts guide for an alternative PC build for EZ2AC. This build is recommended for those who just want to run the newer games on their machines and don't care about the hardware being exactly 100% one to one. The parts here are significantly easier to find as a result and are also far cheaper.
This build has been reported to work with Evolve through to Time Traveler (at the time of writing final has not been tested yet) however your mileage may vary.
MS-6555 based PC:
- Motherboard: MS-6555 Intel 845GL Chipset motherboard
- CPU: Intel Pentium 4 Northwood or Intel Celeron Northwood or Intel Celeron D Prescott 2.4GHz or higher. Socket 478
- RAM: 1GB DDR SDRAM
- GPU: NVIDIA GeForce FX 5200, 5500, 5600 and 5700 ""PCI EDITION""
- Sound Card: Creative Sound Blaster Live! Value 2
- IO: Custom ISA slotted IO card
- OS: Windows XP Professional
It's worth noting that using the 2.4 GHz Celeron will definitely cause stuttering problems and framedrops while playing songs with BGA ON. You will notice it especially with PIU songs. With the 2.8 Pentium the issue is almost unnoticeable so having a Pentium CPU is largely recommended.
The MS-6555 uses the 845GL chipset which does NOT have support for AGP. To get around this you will need to use a graphics card on the PCI bus instead. These can be found relatively cheaply on ebay.
Because of the lack of an AGP slot, you will be unable to install the GPU upgrade that Time Traveler and above use. However as this GPU upgrade was largely useless anyway I have heard people with this build report that Time Traveler runs fine. Again, your mileage may vary.
If you want the original part, here's the link to the video card supplied from EZ2AC team if you buy a kit: 
It is worth noting that by default this build will NOT FIT IN THE STOCK PC CASE. The board is mATX sized so the standoffs don't line up. You can still fudge it in there but you'll be required to run the power supply outside of the case. You're better off just mounting it all in a new PC case.
The original mobo has a jumper setting near the CPU socket which changes the FSB frequency to 400/533 MHz or auto. The auto setting usually runs the system at 533 too. If you set it to 400 the CPU's clock speed will be recognized by the BIOS as lower than it should so the system doesn't run at full speed and you'll experience a similar stuttering problem as seen when running the Celeron.