Yeah, you can only get Arctic down to 1.5mm thick (which is what, 15Amps at 240v?), but it's meant to be rough & ready cable for jobsites and outdoor use, so it has to be thick... :\
I find though that with Hoovers, if they have a predominantly white colour, then you can get away with using a white cable, just as I did with one of my Juniors (surprisingly, the cable was a genuine Hoover spare too!! With a modern moulded plug though, I hate moulded plugs), I think all you'd need for these constellations is 0.75mm cable, which is rated for 6Amps (or 1440w) at 240v, and you could make your own up to any length you liked...
As for other colours, good luck with that, I've looked about for coloured cables online, and generally, they tend to either not make them, or make them for a high cost than a simple generic white, I think there are methods for dying PVC coated cables, but I haven't a clue how that works... :S