Welcome to the forum.
I've just got rid of my 08 Jazz (56k miles), px'd for a 2012 1.4i-VTEC ES. Like you, I looked at a Civic but found that my wife and I didn't fit it all that well because we are both tall! The thing about the Jazz is that it is a bit like Marmite, you either love or hate them, not many are indifferent. With sites like Club Jazz, people post if they have had problems or need advice, but that doesn't make the car bad, it just means some have had problems. Other posts on here having nothing but good to say about the make.
What attracted me to the Jazz was it's reliability and fuel economy and the fact that you still see loads of them on the road in vgc at over a decade old. Bottom line, if you like the one you are looking at, give it a go, I don't think you will be disappointed. I have personally not had any of the issues posted here on either Jazz I have owned.
Incidently, with the back seats down, I recently managed to get two fridges in with a bit of wriggle room at the sides. The Jazz really is cavernous inside, a feature I personally love.