Allow me to help as I have some experience in these matters garnered during those hot summer days in the Sudan…
For the sake of nothing more than a certain element of style that will certainly impress the ladies at such a soirée as you describe, dispense with the banality of the gentex visor and opt for a cashmere scarf draped casually around the collar that could be rearranged in a trice to shield the eyes from anything unseemly. Alternatively, you could face in another direction…
I have never much cared for the gewgaws of green or yellow visors, preferring to have a transparent reservoir filled with Chartreuse of the appropriate hue and secured to the forehead, when filtration is no longer required, a swift suck on a well placed straw will return your vision to normality (for about 15 minutes as I recall).
The power of the fan you seek is 7 (although in the good old days it used to be just a gnat’s short of 9, damn that EU and it’s namby-pamby ways). I have found that the air-cooling system from a 1967 VW microbus, such as one might find abandoned about 46 miles west of Marrakesh on the old camel trail toward the garden of unearthly delight that is the coastal settlement of Essaouira, does the trick quite well. Simply pass the exhaust through a couple of hookahs (nasty business when I first misheard those instructions, I still wake up sweating) and you will have enough breathable air to blow a gerbil clean off a ping-pong table. Worth doing just for the look on the little blighter’s face!
Anyway, good luck old fellow, I honestly have no idea what you’re going on about but you seem a decent sort, couldn’t lend us a fiver ‘till the weekend, only gone and logged on without me wallet see and it’s hellish hot, could just do with a swift one to banish a couple of demons, go on…