The "best" is kinda' relative to what is important to you (price, looks, etc.). I went with Wilwood because they are good quality, they have a kit for my car, and I think they look cool. I converted my stock 10" drums to 12" disks using a Wilwood kit that I bought through Summit.
The kit included every nut, bolt, bearing, and bracket necessary to do the conversion, but it did not include a master cylinder ("MC") or any plumbing. I added a Wilwood MC since I was going to upgrade my stock, single-pot MC anyway. I also paid extra for the Wilwood proportioning valve and soft lines to the calipers. All-in, it probably cost about $1200. On the plus side, the instructions were really good and everything fit together without any issues. Wilwood support is also pretty good. I called them several times with questions and the representative was always very helpful, even though I was ordering my parts through Summit. They even helped me choose the right MC for for my car. After talking to the rep, I sent the first MC I ordered back to Summit in exchange for the right one.
The new brakes have been great! I really like the way car drives and stops with them.