Hi Westy,
I took my Dell laptop to Radio Shack (I think it was; if not them, Best Buy or similar store) and they found a 12v charging kit that comes with a variety of plugs. We tried them until we found the plug that fit the Dell.
For most of the Idevices I use a simple car charger cord. I also bought off Amazon a Vority "Fast and smart Duo 31cc" charger plug that allegedly charges devices faster via twin USB plugs (one plug charges at 2.1A for tablets, the other 1.0A for phones)
We charge my wife's Kindle and MacBook Air by small inverter. I never got around to seeing if there was a 12v option for those.
It's a bit sad to see how many damn plugs and cords we have. I labelled them all or I'd never keep them straight.