Gem, you really need to read the entire thread carefully. It will clear some things up for you, especially re: dogs, guests, and routes.
For the rest, here's the deal. The degree of difficulty and equipment requirements are going to depend on who shows up. It's a come-one-come-all trip and I don't want to exclude anyone by setting an equipment requirement. That said, if we end up with a group of well-equipped trucks, you can bet that we're going to see some challenging trails.
The only equipment we can't compromise on is recovery points. You must have strong front and rear recovery points so we can winch/yank you if necessary. I'm a Defender owner so I can only speak for them: you'll need something stronger than the stock tie-down points. If you're not sure about this requirement, speak up and we can help.
The most important thing you'll need is a truck that runs well and is well-maintained. At times, we will be 200+ miles from the nearest mechanic. You're looking at a $1,000+ tow and days of lost time if we can't fix a breakdown on the trail. Please do your friends a favor and don't bring a total-pile-of-shit truck on this trip.
I will be bringing the usual Defender spares, along with a good set of tools, including air tools. Disco owners will want to bring appropriate spares for their trucks.