Hi Llamatron,
I have 2 Konas (Fire Mountain and Kula Deluxe). Both are excellent bikes, Kona is a quality make. Never be tempted to buy a �200 bike from a downmarket shop, you'll end up with a heavy lump and disappointing cycling. As you have �400 why not look out a specialist cycle shop and see what's available from other leading makers such as Specialized, Cannondale, Trek, Giant, Marin, etc.
Inevitably a year-old bike will be cheaper than the very latest model, I'd go for last year's, save up to �150.
I did a 25 mile trip on the F-M yesterday, very comfortable. I cycle to work (4 miles) and drive only with reluctance. Presumably it is pretty flat where you are ? I am on the edge of the North Downs and it is up and down everywhere.
Here is a good site to browse around and see the sort of thing you can get for your budget.
http://www.evanscycles.com/
Ask for a test ride, different frames have different feels.
Enjoy your cycling !