Advice Please, First ever build

[ThunderWyrm]

I've decided to earn the joy of assembling my own computer, and make use of some salvagable hardware. I have 'some' PC know-how, but am still a major newb, please cut me some slack on this. I want this to be a media/HTPC, able to playback movies/music from my collection (Ext. HD, USB 3.0), and also play Diablo 3 on my 52" flat screen. I have some parts I'd like to use to keep initial costs down, but know there will be upgrades. I'd like to keep it budget in cost, but currently am under my goal.
What I ask of anyone willing to help is, 1) Are there cheaper options for the same performance? 2) Is there better performance options for minimal cost increases? 3) Is the build I have laid out as compatible as I believe it to be? (Newb Q?, sorry )

MoBo - Gigabyte GA-Z77-DS3H LGA 1155 Z77 ATX Intel - $109.99 (-$50 MoBo/CPU combo = $59.99)
CPU - Intel Core i3 3225 3.3GHz LGA 1155 Processor - $119.99
Gfx Card - GV-N630-1GI NVIDIA GeForce GT630 1024MB - $64.99
RAM - Corsair Vengeance (2x4GB) 8GB DDR3-1600 - $46.99

HDD - 1x250GB & 1x500GB WD HDD, but will be replacing at least one for an SSD - $0 - Own it
Case - RAIDMAX Scorpio ATX-868WBP Black ATX Mid Tower - $0 - Own it
PSU - 420watts PS2 ATX12V Power Supply - $0 - Own it

I'm concerned the PSU is on the weak side, and that the RAM and Graphics card are overkill. (Maybe GV-N210D3-1GI Rev3.0 NVIDIA GeForce 210 1024MB ($37.99), and only (2x2GB) 4GB DDR3-1600 ($31.99). Nothing is set in stone, but I would like the CPU/MoBo combo bc I like the USB 3.0 slots, and it seems like a good deal with the $50 off, otherwise I'm open to suggestions. I'm taking these prices from my local MicroCenter as they typically are my cheapest alternative. Thanks in advance; I look forward to learning.

 

[g-unit1111]

You don't need a Z77 motherboard if you're not going to overclock. Get an H77 motherboard instead. Instead of a GT630 get a Radeon 7750 - it will be $30 more but it will be a far better GPU in the long run. Plus the Radeon has native HDMI and is easier to configure on large monitors than NVIDIA is, in my opinion.

That PSU will be very weak - you'll want something from Seasonic or Corsair. The Seasonic S12 II 430W is one of the best low wattage PSUs on the market. If you don't want that much power the Antec Earthwatts E380 is another solid choice and it's only $50.

You can definitely reuse your case and hard drives. You also don't need really fast RAM - for your uses 1333 will be finne. Get Mushkin Silverline if you can - they make good products.

 

[ThunderWyrm]

Thank you, you're absolutely right, I don't need that much speed from my RAM. And the video card does sound like a much better trade-off. Cheaper RAM = Better Video Card After the combo discount, I can't find a cheaper or equal H77, so I'm planning on sticking with that MoBo unless there's a performance issue involved....?

 

[g-unit1111]

Thank you, you're absolutely right, I don't need that much speed from my RAM. And the video card does sound like a much better trade-off. Cheaper RAM = Better Video Card After the combo discount, I can't find a cheaper or equal H77, so I'm planning on sticking with that MoBo unless there's a performance issue involved....?

There's no performance issue but again you don't need it if you're not going to overclock. I'd suggest something like this: http://www.newegg.com/Product/Product.aspx?Item=N82E16813157302

For video card I'd suggest this: http://www.newegg.com/Product/Product.aspx?Item=N82E16814102969