I'd only use tyre sealant as a very last resort, a lot of puncture repairers won't work on tyres that are filled with that sealer gunge, or at the very least they'll charge you extra for thoroughly cleaning it all out so that the vulcanisation process can be successsful.
I've not got non-runflats on my Zed - yet - but my previous MX5 had no spare wheel, just a bottle of the gunge and a small tyre inflator which plugged into the cigarette lighter socket. Being very reluctant to use the tyre sealant in the event of a puncture, I purchased a small puncture outfit which will actually plug the hole. This one is a great bit of kit unlike the usual crap sold via e.bay etc - it actually uses proper mushroom shaped plugs and they work, I know that because I've used it on the wife's Focus twice now. One of the plugs - in a rear tyre - is still in there after approx 9 months and 8k miles - it never goes down. I was so impressed with how secure the plug was that I decided to not to take it and have it repaired at a tyre fitters - the one in the front tyre was taken for a proper repair by the way, just for safety but I guess even that would have been fine had I left it.
The kit in question is this one: http://www.stopngo.com/ It's probably easier to take the wheel off to carry out a repair so you'll need a scissor jack to lift the car.
I also carry a pack of those little red tyre plugs in the boot that Halfords sell: http://www.halfords.com/motoring/breakdown-emergency/breakdown-kits/plug-go-7-piece-tyre-repair-plug-kit I'd use these just to do a quick repair to get me off a motorway or other road where it'd be dangerous to linger for too long. I'd still prefer a spare wheel, but things like this do lessen the impact of a puncture if you don't have one. Being a biker, I've had to use the roadside repair kits several times and most are ok, but the Stop 'n Go thing is the best I've ever used by a long way. I've bought another one now to keep under the bike seat.
