Rambler, I don't have any experience with RVdirect.com but I've seen several discussions about them on Escapees Discussion Forum
and RV.Net Open Roads Forum
. As I recall, the opinion of most who had done business with them was favorable.
I wouldn't consider taking a cross-country trip as a newbie to be lacking sound judgment, more of a small adventure. You can learn a lot by participating in the two discussion forums above plus you'll find other RVers to be very helpful when staying in RV parks along the way. It should be great fun...