Re: Leader and Tippett help
I suggest you buy one leader for each one of your lines (if it would make you feel better, buy one spare). Buy a leader that terminates a couple of sizes larger than the tippet you want to fish. I tie a perfection loop at the end of my leader. I can then attach a length of tippet to the loop, or tie my tippet material to a length mono/flouro/tippet a size or two up, then tie that assembly to the loop. I usually don't carry more than two sizes of tippet material.
Your leader should last a long time, with two or three tippet spools you can attach various combinations of tippet material to end up with whatever length and tippet size you feel like fishing.
I personally fish a short line and a long leader tippet. I usually fish about a 7.5' leader and then attach a tapered tippet (as described above) of about 6 - 7'. I do fish almost exclusively dry flies, so if you are fishing nymphs or streamers, your leaders will probably be different.
The only other advice I'll give you, don't sweat the small stuff, if you are in the ballpark, it will work out for you.