I have a similar setup working with coax cable from wall to cable box input, then coax cable from cable box output to Tivo input, then component cable from Tivo output to TV. I do this on a couple of Tivos. However, my Tivos are Series 2 models (not HD) and I am using the component cable between Tivo and TV because I can, since it provides the best quality image on the TV, when I am watching the TV live. Also works well with composite (red-white-yellow) cables between the Tivo and the TV. For channel control, one Tivo is connected to the cable box using a serial cable (because I can), while the other Tivo uses an IR blaster positioned in front of the cable box window. In both cases, I have an IR blaster from the Slingbox positioned in front of the Tivo windows, and I use a virtual Tivo remote on my Sling Viewing application (can use both the web browser based version and the standalone Slingplayer version) to control the Tivo, which then controls the cable box.
There's a bit of a lag -- just under one second or so -- between a press of a key on the virtual (Slingbox) remote and the "reaction" of the viewing screen to that keypress, but it does work for me.
If you want to watch your TV programs in HD coming from your Tivo, then I think you MUST use component cables, as there are often problems reported when you attempt to put HDMI cables anywhere into the loop, due to some sort of "security" issue when attempting to sling the HD imagery.
Note also that slinging HD imagery requires much more bandwidth than the standard definition slinging that I am doing, so you really need to have internet service at the physical location of your Slingbox with quite high UPLOAD speeds ( 4 megabits per second or greater?) if you want to get the video without stuttering or stalling over the Internet to your remote computer location for viewing.