Honestly, I wouldn't bother with an expensive PDU and an electrician and stuff.
That $900 basically pays for an entire low-end (4 x HD 5830) rig.
Why don't you wire some kind of adapter cable that routes one 110V circuit to a $5 power strip A and the other 110V circuit to a $5 power strip B. Then, you start by plugging in two rigs to power strip A and two rigs to power strip B. This will definitely work. So far, so good.
The elephant in the room is what your circuit breakers actually are.
20A each? This is what I had in Palo Alto, and I maxed them out.
35A each? 30A each? 40A each?
Check the circuit breaker panel. The circuit breakers should be labeled with the office suite #.
If you cannot clearly identify the circuit breakers, buy a $29.99, 1000 W electrical space heater at Walmart.
Plug it into power strip A, while all miners are mining, and turn it on.
Then repeat for power strip B.
If the circuit breaker doesn't fall, you're good to go for another 2 rigs (one goes into strip A and one goes into strip B).
Now you got 6 rigs.
Rinse and repeat this simple test to get to 8 rigs.
I'd stop at 8 rigs, 4 on each side, for a symmetrical load.
Edit: In case a $5 power strip is only rated for 10 A, you'd want more than one for each of the 110 V circuits. But the principle remains: No need to spend $900 on this.