1. i modify pretty much every pattern for use for my children. mine are currently AI2/ sham pocket hybrid and they have gussets. the inners are microfleece, hidden breatheable nylon (for waterproof layer) and recycled material outer. i have a dozen made for DS and i wash them every couple of days. I dont know about anyone else but I find gussets very important for my breastfed DS as it keeps all the poop in. I am using the free wee weka pattern for him, it however does not fit my DD well, so I use ottobre pattern for her and it worked well, her is minus gusset but they are also AI2/sham pocket hybrid.
2. I bought microfleece in Walmart, they were on sale, i think it was $7.98 a meter (i am in canada). I believe i got about 2 - 4 inners from it depending on how I position it. The nylon is fabric is pre cut and my mom got it for me for $3 for a pack of 10. the recycle outer is whatever I have, it can be tshirt, flannel sheets, denim and whatever I hv around the house :-) So total cost? under $10 per diaper. my soakers are all prefolds that i picked up from freecycle.