Finally pulled the trigger on these bulbs which are well rated and reviewed.
It's currently $299~ after 20% discount at Powerbulbs. So saving a further 20%~ on top by purchasing through Amazon.
It's going on a Golf MK7 for reference, but is a common Low Beam bulb for a lot of Euros.
Great review by Headlight Revolution over here at YouTube
Stats from review
The selected bulbs below are the ones I've found that are frequently being compared with each other in the research I've done.
Osram Xenark 66340 Night Breaker Laser
Low Beam: 1,310 Maximum Lux
High Beam: 1,610 Maximum Lux
Osram Xenarc Cool Blue CBB (Cool Blue Boost)
Low Beam: 810 Maximum Lux
High Beam: 1,410 Maximum Lux
Osram Xenarc CBI (Cool Blue Intense)
Low Beam: 720 Maximum Lux
High Beam: 1,580 Maximum Lux
Philips 42403XV2C1 X-tremeVision Gen2
Low Beam: 700 Maximum Lux
High Beam: 1,390 Maximum Lux
Prices for the other bulbs
OSRAM D3S XenArc Cool Blue Boost (Duo Box - 66340CBB)
$204.70 at Amazon UK
$252.14 through Powerbulbs
OSRAM D3S XenArc Cool Blue Intense (Duo Box - 66340CBI)
$182.90 at Amazon UK
$228.50 through PowerBulbs
Philips D3S Xenon X-TremeVision GEN2 (42403XV2C1)
$258.54 for a set of 2 at Powerbulbs
$359.98 for a set of 2 through Amazon
cheers now i need these bulbs in my life.