In short, yes.
I also have Comcast and I am using the Motorola box (forget the model) that has both HDMI and component connections. If you are not familiar with HDMI and component connections, you may want to read up on that first. Many newer cable boxes implement something called HDCP which will effectively block the SlingBox from working properly. Some other tips:
Purchase the SB 500
The best resolution I can get is 720p on my target TV - the 1080 format does not jive between the SB and Comcast
Use wired network connections as much as possible
My cable box allows both HDMI and component output at the same time - many don't - there is a specific adapted that Sling recommends but it's a bit difficult to get.
To change the channels, I don't use the SlingPlayer app - I use the Comcast app
The target TV will need a Roku player, Chromecast or Apple TV box to receive the Slingbox output. I've used both Roku and Chromecast (Chromecast is a little easier to use)
Big caveat - Sling is barely supporting these things anymore. They will sell you one but upgrades are non-existent. Many features have been hanging for years. You will mostly need to learn all of the technologies on your own. Good luck!
Can sling box be used for the following. I have comcast cable on a TV so can a sling box be installed on the TV that is local to comcast services so I can then watch all the comcast cable channels I subscribe to on a smart TV located in another state. On that TV I have no comcast but I have internet for the smart TV. Also from the remote smart TV can I remotely control the local comcast i.e. can I change channels? Thank you