[LD1]

I have poured a lot of concrete in my day and I also think the rebar is overkill.
It is also more expencive and a big hassle. I would use the wire and also have them add fiber to the cement which will also make it stronger. 4" will be pleanty thick. I am going to pour my garage in a few months and it will be 4" thick. I also agree that you need a good base. Around here we use #57 lime stone. (3/4"-1" stuff). 4 inches of that and it will lock together and some of the concrete will seep down into it and it will be a lot stronger than 4 inches poured on dirt.

A couple of tools that I havent heard mentioned yet
1. A good transit-we usually borrow one from work
2. A power screed-I think only like $35 to rent, well wort it
3. A bull float- again not vert expencive and you dont have to walk on the concrete to finish it due to the long handle, but this depends on how yo want it finished.

Another thing I would suggest is to use the transet and pleanty of grade steaks. A floor that big, if you only use your form boards as a reference, it is real easy to get low spots in the floor. It may look good but you will know it when it rains. Another thing you may want to do if you can get a transit is to slope your floor all one direction. just a couple inches every 10-15 foot is pleanty and it will really help when it rains or if you want to hose the pad off.

Finally, about the wire always ending up on the bottom. What we do is once the concrete is powred and leveled, and your just waiting on it to set up enough to finish, we will start at one side with a hook and start pulling the wire up into the concrete. Don't worry about the boot prints because when you get done pulling the wire up, use the bull float and start leveling again.

Good luck to ya