It's a pretty cool part of the world you are heading to.
Vegas is great, been there 5 times. The strip is worth seeing for sure, but I like old Vegas better for personality. As others have said shopping is very cheap in the US at the outlets, the last 3 or 4 trips I've done there I really have travelled with an empty suitcase and bought clothes there, for all the family. Lots of cheap kids clothes and shoes, makes it worth while buying the next couple of years worth of outfits.
Accom is very cheap in Vegas, we always stay at the Signature apartments in the MGM, very flash, and you'll get them for about $120 a night. Lots of other hotels are 1/3 of that price, so cheap.
Very easy to hire an RV and trip around in that, there's about 5x as many RV's on the road there than there is caravans and campers here, they really are everywhere. RV parks at every tourist destination too, you'll pay about $40 a night. The little food diners along the road are a fave of mine, love the American style ribs, 1 serve feeds 3 normal people almost.
Have to disagree about Hway 1 being better than the Great Ocean Road, never heard anyone else say that that has done both, it is a good drive though. From Vegas, the least impressive thing would be the South Rim tourist area of the Grand Canyon, down the bottom of the Grand Canyon is pretty cool, but standing gat the main tourist lookout, the little township of the Grand Canyon I'd skip myself. Horseshoe Bend down near Antelope Canyon is stunning, 100x better than the main GC area, IMO.
Bryce Canyon is great, Xion is one of my favourite parts of the world, you could easily do 3-4 days there, but some of the walks are 8 hours long, but so worth it. Death Valley is pretty cool, totally the other direction to the other locations but easily worth a few days. You will need to hire a 4WD to see many parts of it though.
Monument Valley is a pretty decent hike from Vegas, lots to see, but that is a lot of driving.
The Hoover Dam did nothing for me, LA did little for me, although it is kind of fun driving through Rodeo Drive and Hollywood, and I did enjoy Venice Beach and one of the Piers, but neither were like I imagined. Venice Beach was much grottier and dumpier than I expected.
If you do head from Vegas to Death Valley, you can buy fireworks about an hour or so from Vegas, very cheap and many are pretty powerful. Good fun if you have kids with you. If you drive from Vegas to DV to SF, drop into Sequoia National Park for a few hours.
Hiring an RV and living in that for a couple of weeks is an option worth considering, we've hired them 3 times and have loved them. Even Disneyland has an RV park close by. That means you have a fridge and clothes everywhere you go. Some major shopping centres like Walgrens encourage you to overnight it for free in their carpark, but RV parks are pretty cheap so not a big deal.
So much to see !
