American Classic hubs appear to be the lightest right now (in the reasonable price bracket). With Crest rims and non flexy spokes (ie not them Super light Sapims or DT revolution), will get you sub 1500gms for £500 in the AM wheel area.
But, what Northwind says, what’s wrong with your Traverse wheels. You’re not going to save that much weight unless you go all flexy wheels with super light spokes n rims and even then, maybe 200gms saving over the traverse.
If you’re prepared to take a chance with super light stuff , I know you’re not a big or heavy bloke, look at AC hubs, Sapim/DT revolution spokes, stans Apline/Crest rims. The lightest combo will be approx 1300gms and around £500.