I am trying to connect iMac to 2 other monitors as well as my TV. That is a total of 4 displays.
HERE IS MY PLAN!!!-(I'm not rich)  

I have a 21.5 inch iMac that has one thunderbolt port but can also be used as a mini-dvi port. I want to connect that to a [Cirago HDX3DP01 HydraDisplay X3 DP to 3 DP Multimonitor Adapter](http://cirago.com/wordpress/products/hydradisplay/hdx3dp01/) 
This in theory will allow me to connect to 2 monitors with an open slot for my TV. I do question the resolution output. The HydraDisplay supports up to 3840 x 1024 (3x 1280x1024). I'm not sure what that means. Which resolution is it? I know that the 21.5-inch iMac has a native resolution of 1920 by 1080 pixels, while the 27-inch iMacs are 2560 by 1440 pixels. This means at top resolution of the HydraDisplay is cannot support the native resolution of the IMac 21.5 nor the 27-inch. Will this matter when mirroring or sharing the screens as one? (disregarding the TV)  

So, I have several questions:  

1. Will this work?  

2. Is resolution a big deal when sharing screens?  

3. Has anyone ever tried this or have a better way of doing it besides expensive thunderbolt?