If you're curious, the first product I'm trying to make profitable (and the one whose numbers I reference in the video) is at http://whattowrite.org
But, as I say, the stats on it are pretty bleak at the moment (I need to improve the funnel performance by ~1000%). I may end up spending 2 weeks invalidating it and then move on to greener pastures.
Regarding the amount of money and number of months it gives me, I chose the amount (10k) in order to give myself 4 months, rather than the other way around. 4 months feels about right. If I could live happily on £1k per month, I would have made it the £4k bootstrap challenge ;)
Thanks again!