Hi Jack,
to be honest, you are pretty limited to your options with 3+ PCI slots. However, if you can get hold of the GA-790XTA-UD4 you should find it does what you want.
http://www.giga-byte.co.uk/products/product-page.aspx?pid=3263&dl=1#ov You won't be able to run with one of the 2 slot graphic cards though, as it would cover the first PCI slot.
I have this Mobo along with a 1090T and 8 Gig of RAM and have had no real problems with it. In fact, as Dark Mantis will vouch for me, I have been pretty ruthless with this board and have done a lot of testing and re-configuring with it and it has taken everything I have thrown at it.
On the downside is the Marvell SATA3 controller, it is the only weakness on the board, as far as I'm concerned but it works OK if you don't expect anything too much from it if you use mechanical hard drives.
Another board worth a serious look is the GA-770TA-UD3
http://www.giga-byte.co.uk/products/product-page.aspx?pid=3272&dl=1#ov. This has 4 PCI slots and is another board that I have put through some quite rigorous testing and has been pretty good. Again the Marvell Controller is this boards only real weakness. Again I have had this board running with the 1090T and 8 Gig of RAM, quite happily.
The only thing to bear in mind with both these boards is that they might need the BIOS updated before you will be able to run with the 1090T and it is something you will need to check with your supplier to make sure they have the latest version.