I-7/I-5 gaming rig help/suggestions

[gandimere]

Hello
I would like to preface this with I know nothing about overclocking
all I want is the best possible gaming box for what i have to spend :O)
It will be used primarily for gaming online , and streaming/possible hookup to a tv(samsung 50 in plasma)
I am wanting to build an I-7 gaming rig (or an I-5 if there is a minimal performance difference)
I have a budget of 800.00 (more if needed however I would like to try and stay at 800)
this is a box only build basically


Parts I allready have to incorporate into the build are:
i will be using a 28 inch full hd hanns g monitor hg281d
Page 3 - Hanns.G HG281D 28″ LCD Monitor Review | ExtremeTech
evga gtx470
EVGA | Products 400 Series Family&sw=
the ps is an hec xpower 1080 800 watt
Newegg.com - hec XP1080 1080W Continuous @ 40°C ATX12V / EPS12V CrossFire & SLI NVIDIA HYBRID-SLI Certified Modular Active PFC Compatible with Core i7 Power Supply
I know what I would like and what fits in the budget is 2 different things but heres a wish list of what i would like , and please tell me if these wants are a poor fit for the budget or a high end as possible gaming rig :O)
case :
If you can recommend better at same cost?
Newegg.com - Rosewill CHALLENGER Black Gaming ATX Mid Tower Computer Case, comes with Three Fans-1x Front Blue LED 120mm Fan, 1x Top 140mm Fan, 1x Rear 120mm Fan, option Fans-2x Side 120mm Fan
gpu:
I allready have this card
EVGA | Products 400 Series Family&sw=

pwr supply
I allready have this powersupply
HEC Group USA | XPower1080

cpu:
I-7 2600 k or I-5 2500k (i dont know enough to decide between the 2 performance/price wise)

motherboard:
i will consider other chipsets but i like the z68 hybrid hdd function and Intel graphics ability
I have been looking at asus , gigabyte and ,msi , and foxconn
an sli motherboard with an z68 chipset (I wouldlike to be able to add a 2nd card in the future or a new card(s)6.0 sata3 and usb 3.0

emory:
what will work on mobo and is best
best possible memory match for board
sound:
onboard or is performance better with add in card?
blu ray/dvd/cd burner
6.0 sata3 hdd
possible ssd? probably wont fit in the budget i have but recommends?
thanks in advance for your help!

[glc]

For gaming, the i5 is plenty good enough, the extra $100 for the i7 is better spent on something else. Performance difference is minimal, you are essentially paying the $100 for hyperthreading.

Best motherboard for your purpose is an Asus P8Z68-V Pro. Best ram for a Z68 is Corsair Vengeance. Onboard sound is fine. Best hard drive is a WD Black SATA 6.0, preferably with 64mb cache. Best SSD for OS and programs is an Intel 510, but that's out of your budget - what I'd do is get a 40gb Intel 320 and set it up for caching. Anything but a Samsung for an optical drive.

[gandimere]

can you be a little more spefic on the memmory choice?

heres the lineup at newegg.
Newegg.com - Computer Hardware, Memory, Desktop Memory, DDR3 1600 (PC3 12800), 16GB (4 x 4GB)

[glc]

Whatever Vengeance you want - 1.5 volt DDR3-1600, dual channel kits. You do not need 16gb for gaming, 4gb is enough, 8gb if you really want.