With the rear bike rack, if your thinking of a design such as what I have.
View attachment 55935
I strongly recommend you DO NOT DO IT.
My chassis has been strengthen for the rear bar similar to your drawings. On a recent trip a friend followed me and filmed how much the bikes moved, it wasn't pretty. The bikes bounced up and down a lot, it wasn't due to the bike rack, but the rear bar flex.
To correct it, i'd need to make longer rear bar mounts to spread the load further along the vans chassis, being worried about a knock on effect with this idea I thought a bit differently and did this.
View attachment 55936
The tool box by the way is this.
https://www.kincrome.com.au/gullwing-alum-truck-box-1600mm
A webber 2200 fit in it just, and a honda 2.0 fits sideways also.