We pull what sounds like the same 5er from the weights (cougar 176rls) with a 2007.5 chevy 2500hd ext-cab longbed 6.0L 3.73. Plenty of power and brakes, no issues pulling packed with full water. Great match, IMHO. Unless your a diesel-head you won't regret it. ;-)
We tow with a 2007 Chevy 2500HD 4x4 6.0 3.73 Longbed. Currently pulling a 2011 Cougar 276rls (Dry Weight - 7143, Payload Capacity - 3037, GVWR - 10180), pretty close to the 5er your talking. I am completely comfortable with this setup, it seems a great match. We aren't real heavy packers, but tow with full water much of the time. We have not towed the Rockies yet, but I don't worry about finding it an issue. The only limit you'll be pushing is GCVWR, but pack responsibly and you should be fine.
Having driven 4 cylinders for 35 years I don't fear the rpms that many do. The 6.0 is a great engine, if a bit thirsty at times. Overall we range from 7.5 - 11mpg, average around 9-10. Sometimes the worst mileage comes in the flat states (we live in IL) due to wind. Hills have the weird effect of increasing mpg for the most part.
Well, if you can restore a truck you can build a camper (teardrop or small standie). Check out the Teardrops and Tiny Trailer forum for a gazillion ideas (esp. the gallery) and enthusiastic group support.
Teardrops and Tiny Trailers
Long live the rotary engine (unfortunately former rx2/rx3/rx7 owner).
If porcelain is only stained I would use muriatic acid. There isn't much it won't clean off porcelain. Tip, for really tough stains keep brushing it on and let it sit for an hour. After a few hours it will be gone. Father and I have resurrected countless toilets/lavs/tubs and other porcelain things with it. Just be sure to take extra caution as it will burn any soft tissue quite readily and quickly.
About the sweet spot myth, I would challenge anyone with any vehicle to drive 1000 miles at 70 and 1000 miles at 55 and compare the MPG or you can choose slightly different speeds as long as they are far enough apart to really measure a difference. The low speed is always going to win as long as it isn't so low as to drop the trans down out of the top gear. I think people think their engine has a "sweet spot" because they are used to driving at a certain RPM range and like the way the engine sounds. If they slow down, the engine may seem to "lug" a little so the thought is that it will use more fuel. I don't think so. I don't think you will get better MPG at 65 than you would at 62 or 60 but the difference might be difficult to measure.
As a gasser driver I say get a Scanguage, you will quickly discover there are sweet spots. They can certainly change due to terrain/wind, but they definitely exist. On flatland stretches (we live in IL) our setup gets worse mpg at around 48mph than 55 mph. And I get worse mpg at around 58mph than I do at 63mph. I generally drive around 63, depending on terrain and wind. I would say get very familiar with your setup to get the best out of it.
Not a 12 volt option, but we most always run a fan in addition to the air conditioner, esp. on really hot days. We have switched to an oscillating tower fan (like this Lasko Tower Fan). Very small footprint and puts out a good deal of air (these are essentially very tall squirrel cage fans in a pretty case).
I just use a laptop (freelance web development) and the dinette. We use 2 of these at home (airdesk: http://www.airdesks.com/catalog.asp) and love them. I am considering sticking one in the 5er next trip to give it a whirl from my recliner.
We took a 2 week tour through Louisiana in Oct last year, had a fantastic time. From relaxing, sightseeing, eating, and festivals/music/dancing, Louisiana is a great time.
Lake Charles, LA - Sam Houston Jones SP, very pretty
Lafayette, LA - keeping our camping location a secret, stay anywhere around Lafayette
Lake Fausse SP, LA - Lake Fausse SP, remote and quiet
Grand Isle, LA - Grand Isle SP, right on the gulf
New Orleans, LA - New Orleans RV Park, block from Treme
Bit of a travel log here: http://sarahdaveely.travellerspoint.com
We were are Holliday Lake State Park for 3 nights just a couple of weeks ago, very close to Appomattox (13 miles). In Spring of 2011 they added a new loop (with new bathhouse) for larger RVs, it's very nice and very up to date. Sites were huge and very far apart. The park has a beautiful lake with sand beach (and lifeguard) but it is maybe a bit remote (we got wireless here though, phone (at&t) and internet (verizon)). I would definitely stay again.