Congrats
You might also want to think about an upgraded fan in the bathroom to help cool off the trailer. Fan-tastic makes a good vent fan and with a vent cover like the MaxAir ( I have 2 of them) or Fan-tactics version you can run your fan or have the vent open in the rain. Dealer can install this for you.
Walmart is awesome. Often same stuff but cheaper.
Sewer Hose - I like the Rhino brand and you might want to look for a support like the Camco Sidewinder
http://www.walmart.com/ip/29764423? it's stiffer and easier to work with than some of the others.
Also a clear pipe segment like
http://www.campingworld.com/shopping/it ... pter/16835 allows you to see if you got everything nasty flushed out of your tanks.
Drinking water hose - as others have suggested. I like the plastic end it's easier to grip.
Surge protector (30,50 or both) - I'm sure you have a 30 amp rig so I second the Progressive Industry 30 amp EMS (energy management system) system
http://www.progressiveindustries.net/ems_hw30c.htm either installed inside the TT with a remote display or the post. I prefer the internal so it's protected and I don't have to think about it. Also the PI system has a lifetime warranty vs the 1 year Surge Guard has.
Voltage regulator - not required if you have a Progressive Industry EMS. The PI or Surge Guard will shut off the power until voltage returns to normal. There are voltage regulators but the cost vs the actual need is low. I personally don't know of anyone actually using one, I've only read of a couple of people in RV.net that use them. Not that common.
Surge guard lock - not required if installed inside TT.
Wheel lock - if they want the tire that bad I'll by a new tire. If your talking about stabilizing the trailer by locking the two wheels together then I recommend X-Chock
http://www.campingworld.com/shopping/it ... pack/49876Wheel chocks - I carry 4 just incase I lose 1.
Propane lock - you can lock the bottles but can not restrict access to the valves. I don't lock mine so if there is an emergency I can remove then from them from the trailer.
Battery lock - my battery is inside a locked compartment
What I don't see is a water pressure regulator. I like this one
http://www.campingworld.com/shopping/it ... Am768P8HAQ cause I can adjust the pressure and it has a higher flow rate than the $10 kind that they may give you with your new TT. More flow means a better shower.
You'll also want a 50 amp male to 30 amp female
http://www.campingworld.com/shopping/it ... male/27987 The handles are nice for "pulling the plug" keeps your fingers out of the way. Also if the 30 amp outlet is worn you can use the 50 amp plug. According to the boards the all in one "hockey puck" style tend to overheat and breakdown.
There are tons of gadgets on the market. Get the basics and see which of the toys you actually need. Buy them as you need them.
I find these use full
Dump Station wrench
http://www.campingworld.com/shopping/it ... ench/70031Drain hose wrench
http://www.rvwholesalers.com/catalog/kw ... Ajif8P8HAQAlso a box of latex gloves for handling stinky things.
Enjoy...