What you are looking for is called a HDMI matrix switch.
There are a number of different manufacturers out there which range in price and quality significantly.
More entry/mid range models can be found from companies like Atlona, Gefen, and Aurora Multimedia.
At the high end, companies like Extron, Crestron, and AMX provide really top-shelf solutions.
I am not sure how the Octava units stack up against those units or against the higher end units as I have not ever used them.
The difference between cheap ones and good ones is that the good ones will have full EDID management, they may provide options for scaling content to displays, they all pre-authenticate all the connections to deal with HDCP. This means that they switch faster and they don't blank displays during switching. They also carry a far higher price tag.
So, you need around a 6x4 HDMI matrix.
Doing some comparing, using MSRP:
Crestron DM-MD6x4 - This is a 6 input, by 4 output unit - $3,800 list price - http://www.crestron.com/resources/product_and_programming_resources/catalogs_and_brochures/online_catalog/default.asp?jump=1&model=DM-MD6X4
Gefen - GTB-HDFST-848-BLK - 8x8 HDMI matrix switcher - $2,499 list price - http://www.gefen.com/kvm/gtb-hdfst-848-blk.jsp?prod_id=10503
Aurora Multimedia - ASP-88 - 8x8 HDMI matrix switcher - $5,799 list price - http://www.auroramultimedia.com/?section=products&id=136
Worth saying that 4x4 HDMI matrices cost a good deal less than a 8x8 matrix will run you. So, the ASP-44 from Aurora is $1,999 MSRP vs. $5,799 MSRP for their 8x8.
This item is also sitting out there on eBay which comes from a reputable manufacturer and may do a very good job for your needs...
But, the reality is that you can't really get by with a $200 product with the number of inputs you want to share.