High freq splitter

I have a slimline 5 dish (option 04) with four coax cables running into my home. Today I have 1 cable going to my standard def receiver, 2 going to my hd-dvr and one going to my hd receiver. I want to add another receiver to my setup (HD-DVR) and I will need two feeds in order to be able to connect both tuners on the new receiver.

I have seen the Zinwell splitters for sale and I am wondering if I can use one of these to split one of my existing feeds so that I can feed the new device?