Topband: Best Receive Antenna over Sloping Terrain?

[Ed]

Greetings from Saudi Arabia!  I think a lot about my home QTH in California and how I want to make the most of my antenna potential. 

I have an area that I would like to devote to receiving antennas, that's about 150' square feet. Thought about the DXE Active 4 Sq array but they say installing this on Sloping terrain will degrade its performance. In my case, the slope is about 30-35 degrees, so I'm sure that limits me. 

The transmitting antenna area is about 300-400 feet away, which provides adequate isolation from where I want to install a receiving antenna. Trying to figure out what is most suitable.  In addition to 160m, I am also interested in BCB DXing and some the demonstrations viewed on YouTube are quite impressive!

Would really appreciate some input. I can always provide my home address, where the two antenna areas can be seen on Google Maps. 

73,
Ed NI6S/7Z1ES