to a large degree, be careful of marketing hype. interpret the literature carefully; i notice the Halford Extreme Brilliance are "up to 90% more light". this is not 90% brighter
to the human eye.
my slant on changing globes, is that you do it primarily 'for the look', and expect only a small improvement in brightness. many of the globes are little more than blue-tinted glass. to achieve some of the high Kelvin colours (Kelvin is 'temperature', and different temperatures cast different colours; hence, HID xenons are usually 4300K; higher kelvin looks more blue/purple; lower kelvin is more yellow), the tint can be darker; so a globe that claims 5000K might not actually operate at this light-temperature, but rely on tint to achieve the 'look'. also, higher Kelvin and/or darker tint beyond a certain point will reduce light output
also consider sticking with quality brands like Philips, Osram, PIAA. i've no idea what Halfords are like.
for the 'less essential' globes, like foglights, i prefer something like Philips Crystal Vision (simulates 4300K) or Diamond Vision (5000K) or PIAA GT-X (5000K). for your dipped beams (ie: the globes you rely on most for vision at night), i'd probably go with something like Philips Blue Vision (4000K) or Essential Vision (4000K).