oc3d does nothing but sing the praises of the APU's, and so do a lot of reviewers.
Why would you include a stand alone GPU with APU?
If he buys a separate GPU he should go for an Intel build. That is just silly.
"I then changed to the Corsair CX500 PSU as the 6800k can be crossfired with a 6670 for your brothers gaming and this brings the power draw up to about 400W."
He doesn't need to have the dedicated GPU if he doesn't want to.
GPU with APU is legit. http://www.overclock3d.net/reviews/systems/oc3d_recommended_system_builds/2
Regardless, I would leave out the graphics card until you actually (if ever) need it. Make sure the power supply is able to cope with the upgrade (no more than 500w) and you'll be fine. The APUs do benefit from high frequency ram, but seriously, the 8GB 2133Mhz is over kill. Get some 4GB 1600Mhz and it's more than perfect for you parents.
http://www.overclock3d.net/reviews/systems/oc3d_recommended_system_builds/2
H87 I would be happy to get but I can't for the life of me find a mini ITX H87 so if you can find/suggest one let me know.
Well if the 560Ti will be added later on definitely go with Intel.
"I then changed to the Corsair CX500 PSU as the 6800k can be crossfired with a 6670 for your brothers gaming and this brings the power draw up to about 400W."
He doesn't need to have the dedicated GPU if he doesn't want to.
Hmmh, should be fine without any OC.The 420w seasonic would still be more than enough right?
if he will add a dedicated card,then hell no apu. even if he will stay without it a while. also the cpu found in 5800K/6800K ,the athlon x4 750K/760K paired with hd 7770 will destroy the crossfire performance with apu + hd 6670. not worth it. however an i3 haswell IS better then x4 750K even in multithread,so if he has the budget,hell yeah.from amd get atleast fx 6300,which is similar to the i3 .
now about the futureproofing,if you have the cash for a non K i5 ,go with it. if not get the i3,sell it in 1.5-2 years and get an i5. on FM2 you are stuck with athlons.
The 420w seasonic would still be more than enough right?
Should be. Just make sure if you get it that it has enough cable ports for the whole build and enough Amps to power a GPU and a little extra for everything else.
lets take a look at the gtx 560Ti. it uses 169W at peak in games. 169W / 12V = 14 amps. a good psu that has 400W on the 12V rail is more than enough. for example, a gtx 770 only uses 11W more than 560Ti.so no worries with a seasonic under 500W.