Definitely not Adwords. Overpriced, poor conversions and generally not worth the money once you look at how much profit you're taking after completing a job. Some will say ahh your quality score was low, your ads aren't setup properly. But I can assure you thats not the case - when you're competing up to £3 or £4 per click - Adwords is not the way to go.
Personally, I'd spend £1k on van signage too. Good van signage with a serious graphic designer. I haven't had tons of work from sign written vans, however, it seriously helps with brand identity. People notice and remember the logo and name, then when they do go to search for carpet cleaners they subconsciously recognise your brand and you're more likely to get that click or website visit in the process....
There's my 2 pence...