Quick PSU recommendation requested

[Atragon]

I'm putting together a mini-itx HTPC at the moment, and am trying to decide between a few different PSU options. I am also open to other options in the price range.

I am aiming for a fairly quiet system, which will primarily be used for watching movies or streaming games from a different PC via Steam. It is possible that I will eventually want to put a dGPU in to allow for local gaming, but I will not be doing so immediately.

System specs:
Case: Corsair Obsidian 250D
CPU: i5-4690K
HSF: Noctua NH-D9L /w second fan
MB: ASrock Z97E-ITX/AC
RAM: G.SKILL RipjawsX PC2133 2x 8 GB
Optical Drive: LG Blu-Ray ROM
GPU: None for now, I may either put something like a GTX 960 in later, or hand-me-down from my gaming PC which currently has an Asus Poseidon GTX 980
Storage: re-using a SATA SSD and 2.5" HDD

According to a few PSU calculators, I'm looking at <200W under full load without dGPU, and between 300 and 400 W with dGPU depending on specific choice.

I'm in Canada, and trying to take advantage of Boxing Day specials if possible.

Current shortlist:
Corsair RM650i ($110 /w MIR)
Corsair RM750i ($130 /w MIR)
EVGA Supernova G2 650W ($100)
EVGA Supernova G2 750W ($110 /w MIR)
Be Quiet Straight Power 10 500W ($140)

My current thoughts are either of the 650W units as both offer fanless modes up to higher than my current max load, and have decent warranties. I'm leaning towards the Corsair for the Link functionality, and the indications that its fan is quieter when in operation.

Thanks in advance!

Edit: Corrected CPU to 4690K from 4670K, added information about storage.

[lodestar]

It might be worth thinking about a Platinum PSU, such as the EVGA Supernova P2 650w which is more efficient than the best of the Gold units on loads under 100w. Cheapest I can find is $154 from Direct Canada. See the jonnyGURU review.

[Atragon]

I'd question whether the increased price is worth it solely for the 3-6% efficiency bump below 100W of draw, and ~1-2% under load from the jonnyGURU review. If it has other redeeming features (ie, higher ceiling on fanless operation), or if I'm missing something, I'd love to know about it.

[Abula]

I'd question whether the increased price is worth it solely for the 3-6% efficiency bump below 100W of draw, and ~1-2% under load from the jonnyGURU review. If it has other redeeming features (ie, higher ceiling on fanless operation), or if I'm missing something, I'd love to know about it.

Well a platinum even though its just slightly more efficient, that means you will have less heat buildup, and thus less need of the fan spinning, depending of how you place it could mean less heat inside the case, but Gold is pretty good as it is, its up to you if you feel the price difference is worth it.

[lodestar]

The ten year warranty is a plus. Also you can switch between Eco and Normal modes. In Eco mode the fan might never turn on in your usage but ambient temperature could be a factor. Over a ten year period you would probably get the extra cost of the unit back in energy savings so going Platinum could cost you nothing in that sense.

[Atragon]

Having run the numbers based on jonnyGURU's measured efficiency values, it looks like the RM650i is between $10 and $20 cheaper over 5-10 years compared to the P2 650W.

Having said that, it sounds like the P2 stays fanless for longer based on TomsHardware's reviews of the RM750i and the P2 650W, and jonnyGURU's reviews of the RM650i and P2 650W. (Based on the numbers, the P2 will definitely stay fanless even if I go up to a ~400W draw with a GTX 980 Ti or something similarly stupid while the RM650i might start to spin up its fan at that level, but if I stick to a ~325W draw with a regular GTX 980 it should stay fanless too.)

The extra 3 years of warranty on the P2 are attractive, while the Corsair has a slightly more optimal cable set (no daisy chain on the 8-pin connector) and has Link. First World Problems. I think I'll sleep on it.

Edit: Went with the Corsair. Thank you all for the advice.