As far as I know there is no 'Dark Angels Upgrade Box'
The Veterans box is the entire Dark Angels upgrade sprue. That's all it is. It comes with 5 robed bodies and plenty of cool backpacks guns and accessories. Not to mention other cool stuff like some DA terminator weapons and legs. Including an assault cannon.
Likewise, the Ravenwing Bike squad comes with the Ravenwing upgrade sprue and three bikes. It has everythng you need to upgreade the three bikes it comes with, plus it comes with the parts to make upgrade three speeders into two tornados and a typhoon, or to make one typhoon and upgrade one speeder into Samael's Ravenwing speeder.
Not to mention some other neato bits.
The Dark Angels Command squad (now discontinued) contained both the Dark Angels vet/ugrade sprue and the Command Squad sprue. It was an awesome value and if you ever see one on a shelf...buy it!