Try to get MaxAir vents installed.
You might get a black/gray hose, but whatever they give you will be the cheapest thing they have and not what you want.
You should get propane tanks, at least one battery, and possibly a spare tire (but no spare tire cover unless the dealer has one with their name plastered all over it so everyone can see where you bought (I pass on those :))
You will need to purchase
water hoses (potable) - probably at least 50 feet
power cords - look for the marinco marine style. 50 foot one and a 20 foot one. Size depends on whether you have 30 AMP or 50 AMP service. (for example, a 50 foot 50 AMP cord marine style (Marinco 50A Cordset 125/250V 50 Feet 6152SPP) is on sale now for $701 CDN at binnacle.com
check out a marina or goto binnacle.com for a lot of this stuff in addition to the rv stores - boats and rv's have a lot in common
