Hi Bob
I've gone for Marathon+ simply because many in the forum have used them for long periods without punctures.
your conti's seem to come wih a one year guarantee against puntctures so they must be pretty confident.
Ive never seen the attraction of slime. To me its just a load of crud you have to clean up that renders the tube unrepairable if it doesnt work properly. Adds weight too. At least if anything does get through my Marathons, i will be able to fix the puncture.
necessity is the mother of all invention and speaking as someone that is traditionaly crap at all things mechanical, you soon learn the skills needed to perform the basic maintenance your bike will need. I use utube to watch someone else doing it first. there are loads of videos of the more common tasks.
i'm waiting with interest to see what happens when you try to pump your tyres up
p.s. get some oil or grease on that chain tensioner soon