AsadJ278 :
I have a paranoia of PSU frying pc components thats why im extra careful, which of the 2 has the most risk of failure if any?
Both are quality PSU so you're just about as safe as you can be.
This tier list is pretty widely relied on:
http://www.tomshardware.com/forum/id-2547993/psu-tier-list.html
You'll find the 57 quid GS unit in Tier 1 (the best), and the 50 quid B2 unit in Tier 2.
With either you'd be extremely unlucky to end up with damaged components, but based on reputable, objective reviews the 57 quid GS unit is slightly higher quality.