As a general rule of thumb with these bulbs, the bluer the glass is, the whiter, and thus perceptually brighter the light is. So you are looking for something like:
https://www.ebay.co.uk/itm/H7-H4-H1...583992?hash=item1ef57c50f8:g:xn8AAOSwAn9c1Mt3
Which is seven quid for a pair of blue tinted H4 100w bulbs from a UK seller. If you wait on Chinese sellers you can get a pair of very similar bulbs for about two and a half quid:
https://www.ebay.co.uk/itm/H4-100w-...700148?hash=item48d83076f4:g:0s4AAOSwhVVd3yHU
https://www.ebay.co.uk/itm/H7-H4-H1...583992?hash=item1ef57c50f8:g:xn8AAOSwAn9c1Mt3
Which is seven quid for a pair of blue tinted H4 100w bulbs from a UK seller. If you wait on Chinese sellers you can get a pair of very similar bulbs for about two and a half quid:
https://www.ebay.co.uk/itm/H4-100w-...700148?hash=item48d83076f4:g:0s4AAOSwhVVd3yHU