Best Hair Extensions Possible?!!!!?

Okayy! So last year I bought hair extension on eBay for about $25 because I'm cheap. But that was when my hair was very short, like shoulder length. I now have run into problems with these extensions, 1. They were cheap, so all the hair has pretty much fallen out, and it was originally 100g now it's like 20g! And my hair is pretty thick. 2. Since my hair has grow just above my boobs, my 18" extensions are only maybe an inch longer than my real hair, so they are worthless and 3. They are old and tangled extensions because I wasn't smart enough to take care of them. So now, I am looking for new extensions. My criteria: thick enough for my hair, so I would like to know, people with thick hair, do you use 120g 140g or 160g? Also what length do I get? I want my hair at least past my chest so what length? 20"? And lastly what are the best brands? I have heard foxy locks are the best quality but I live in America and people say they take fervor to ship, and without the clips, the 160g is only 140g and that is a waste of my $100. I've heard good things about Luxy, burt again, for 120g a bit expensive, also heard of Hello Gorgeous but haven't heard any reviews. Need something fitting my criteria in the $50-$100 range, maybe a bit more...thanks!!