Eddy,
Herzlich Wilkommen !
Nice collection and you will find this forum to be really helpful. Myself, transported Belgian to Texas since 1997. This is now home.. ;-)
Perhaps some points of reference to help you out planning your vacation. I'll send you a private message with my email address. Feel free to send me an email if you need advice, directions, help, etc..
If you're flying to LA, drive up to Vegas is not too bad. It's about what you would say, a 5 - 6 hour drive, depending on the stops you make.
Vegas to Dallas is roughly 1,200 miles or 20 hours. If you drive only 5 or 6 day, with stops perhaps, it'll take you four days. When I first moved here, driving from Dallas to Berea, KY is about 900 miles and would take me two days of about 8 hours driving. Now, I'm more used to the long hauls, but 8 hours remains a comfortable drive for a day. I regularly take a 450 mile trip (7-8 hours) down to the Texas Coast to go fishing.
The US is big.... very big.... as Europeans we really have no concept until we start driving around here. I have family in Kentucky (17 hours), Colorado (15 hours). You get used to it ;-)
Once again, welcome on board, have a seat, buckle up and enjoy the ride.