My tip of the day, go for option number three.
And here is why...
The Spa 24 Hours is the second best endurance race in Europe (first is of course LM, third is 24 Hours of the Nuerburgring, fourth is the 24 Hours of Zolder and then there isn't really any good event to follow). As you know, Spa-Francorchamps is in the Belgian Ardennes, which is one of the most beautiful places to be during that time of year. Then, there is an immensly strong field of 60 cars (the FIA GTs, 2 Moslers, a Moggi, a Stealth, a Vertigo and a Corvette to name just a few of the exotica... all jammy jammy motors). Also on the plus side is the Belgian food and drink which doesn't need to hide behind the French one. The Belgian beer is actually a lot better.
Camping is no problem at all as you are used to the LM standard. Try to be there latest on Friday to get a good pitch. As far as I know there's no pre booking of camping tickets. You get your's at the gate. If not, pitch your tent somewhere in the woods. General admission tickets are available at the gate as well. No pre booking needed. Just turn up and join the fun.
Last year's race attracted around 150.000 people, mostly of course from Belgium... and they know why. This year's race is in ten days. So pack your bags and come over.
The official internet site is this:
http://www.proximus24hours.com/index.html . You will find hotels and restaurants and other usefull information on here. Have fun...
Edited because of typos no end, argh.