Roy,
The reason for the mono backing is that if you don't put a few wraps of monofiliment on your reel as an anchor for your super braids, you'll find that sooner or later you'll probably have an issue with the line spinning freely on the arbor of your reel. This is not true if you have a reel with an arbor that has a hole in it so you can tie the line solid, but most reels don't have this and so you must rely on an arbor knot. And with the slipperiness of the super braids it doesn't take much for this knot to slip. You don't need a lot of mono for an anchor but I usually put about 10' or so just so I know that it's got a good bite.
I think the choice of what braid to use depends on you. There are many brands and I think they all have their own qualities. Not all brands offer their line in marked increments and so if you want a line that will tell you what length of line you have out then you'll need to look at the ones that do. I prefer to use a line counter reel for this purpose and so I choose to use one that is bright in color the full length so it is easier for me to see it when I'm fishing. I think last time I bought this I purchased some PowerPro but before that I used TuffLine and no problems with either one. When I'm using jigs for kokanee, I prefer the super lines over the true braids because they really do help make a longer cast easier. My favorites in these are either FireLine or Spiderwire, in that order. What braid you want really depends on you and what you want out of it. Some of them are created stiffer so that you aren't as likely to get it wrapped around your rod tip, which is something that you always have to watch for when you are using braid.
Usually, a manufacturer is pretty good about informing the buyers what characteristics are available in their lines. I strongly recommend that you look up the manufacturers online and read these bits they have written there about their lines to help you make your decision in what you want. I think this is more important for braid by far than it is for mono because when you buy braid, you're going to be able to continue to use it for several years before you need to replace it. I've got reels spooled with braid that is 15 years old and it's still good stuff with full strength.
As far as pound test for the lines that I prefer, I usually spool my spin reels with 8lb test. My level winds depend on what I intend to fish for with them. When my reel is used only for kokanee, or other such smaller fish, I like to use a 14lb test but when I'm gearing up for salmon fishing in the estuary I'm inclined to use 30lb test. I stay lighter on line for the spinning reels because I've found that I have less difficulty with line twist and rod-tip wrapping that way. Once I learned to use the palomar knot, I was amazed at how strong these lines are. I have found that even with the little 8lb line, if I become snagged and unable to retrieve my hook, I have to squeeze my drag down tight and aim my rod directly at the snag up and then pull very hard in order to break it off. And even then, most of the time it will straighten my hook and I'll get my gear back anyway. Just make sure you retie immediatly if this happens.
Personally, if they already have braid on them and I was unfamiliar with braid and all of its little quirks, I would leave the line that you have on them alone and try it out before I changed over to anything else. There are a lot of people who just never do get to where they like the braids. There are some things that you just have to do different in order to use them successfully and that's not what everybody is looking for. I use them myself because I love all the benefits they offer, but I would definately suggest that you try the braids that are on them first before you purchase new line that you may find you hate. Unless of course the line that is on there is rotten or weak or something.
Good luck and tight lines!
LOL, with our three boys (one a boy scout and the other a cub scout) we all thought we pretty much knew all the knots 
