i5 Memory upgrade + voltages

[Orm]

I presently have 4 gig of low voltage memory in my i5 system (old i5, not the new 2500k etc).

Want to upgrade to an 8Gb kit and found the following:

Kingston HyperX Genesis Grey 8GB (2x4GB) DDR3 PC3-12800C9 1600MHz Dual Channel Kit : http://www.overclockers.co.uk/showproduct.php?prodid=MY-094-KS - £48

G.Skill RipJawsX 8GB (2x4GB) DDR3 PC3-12800C9 1600MHz Dual Channel Kit : http://www.overclockers.co.uk/showproduct.php?prodid=MY-060-GS&groupid=701&catid=8&subcat=1517 - £56

Corsair Vengeance 8GB (2x4GB) DDR3 PC3-15000C9 1866MHz Dual Channel Kit : http://www.overclockers.co.uk/showproduct.php?prodid=MY-292-CS - £60

Heatspreaders on the Vengeance are no issue as i'm water cooled.

Looking for the highest performance, most reliable kit - recommendations please. The £12 difference between cheapest and dearest is no issue with memory at it's presently dirt-cheap prices.

 

[Orm]

Just to update, I bought the Hyper X. Reasons were the low-profile heatspreaders and I read some really good reviews that convinced me paying £12 for the Corsairs wouldn't have been an advantage at the moment.

Now to install them!