Tents, no need to spend $300 on a tent. go to hot deals section for tents at www.campmor.com and check out the brand name tents. Kelty, North Face, Eureka just to name a few. The ones i saw $100-$120 range.

Tents have the purpose on 1 keeping you out of the rain and 2 out of the water. They are not intended to be insulation. buy one size larger than you need, one person using the tent buy a 2/3 person tent. The extra room comes in handy if you want to stowe all your belongings inside. Freestanding or stake down? Freestanding allows you to move the tent to a new location easily if you want, stake down means take it all apart and rebuild. I would buy a tube of seamseal and seal the rainfly and the tent itself and you should be water proof.  If the floor is like a plastic tarp, no need for a ground cloth, if heavier nylon get a tarp and cut it down to the footprint size of your floor.  Don't forget to get a lightweight hammer for your stakes, plastic ones save weight Drive your stakes in at shallow depth/low angle 20*, the ground will be very hard and the stakes will bend or break. Don't pitch your tent at a low spot of the terrain, if it rains water will drain to the low spot hence making your dry tent a bathtub.

I have used a Eureka Gateway II for three years with NO problems. I trusted the brand even though I bought the tent at Wal-Mart for $50 and I haven't been disappointed.  I did seam seal it myself, and at about 7 pounds it isn't the lightest around in a two person size, but I only use for cross state rides anyway where someone else carries my gear. Between CNC, BRAG, Bike Tennessee, and Bike Virginia, I have used it for about six or seven events and it has stayed dry in heavy rain, is fairly easy to set up, and still appears as good as new. 

What you usually get for big money is lighter weight which isn't an issue on these rides.  Just look for reinforced stitching at all the stress points, and apply a bottle of seam seal.  Dick's Sporting goods also appears to have 2-person and 3-person models at $50 to $90 depending on whether you hit a sale or not. (I found them AFTER I bought the one a Wal-Mart but the construction looks strong and the price is certainly right.)

I have been using one of the REI 2 person half dome tents for the last five years.  The latest version is at http://www.rei.com/product/728308
I tent alone and find this two-person tent is great - the two vestibules provide ample covered space for my bags and keep them out of the tent so there is tons of room inside.  If you plan to put two in the tent, I would go with the 3-person version.  Additionally, purchasing from REI is your way of thanking them for supporting this ride (despite the bike inspection form).

I'd rent from BUBBA! ( www.bubbaspamperedpedalers.com) Since you don't need the tent for a looooong time before the next use... Bubba will set it up, provide a nice air mattress and tot your luggage and you don't have to look that hard to find it.  He also provide a towel and chair.  It really is a no brainer!