TV monitor / screen for sat TV

I am confused as to what screen or monitor is suitable for watching satelliteTV.

We have sat TV at home but a thought has occurred to me for when we travel in the future. We are not avid TV watches but there has been occasions when remote that it would have been handy to pick up the weather or the news when radio reception is non existent......

We have a Kenwood sound system (DVD and GPS compatible) in the cruiser that has TV capabilities (the book says with suitable receiver). It has a plug in the back for a dedicated plug from a dedicated Kenwood TV receiver....... but also has the RCA red, white and yellow input terminals in the back as well.

1) If I plugged the RCA cables from the set top box into these is it as simple as the unit would display TV?
2) If not, then provided I could find a suitable adaptor from the set top box RCA into the Kenwood dedicated input I assume this would work
3) Is there an alternative that I can send the set top box output into the laptop and use its screen?

screen size is irrelevant to me as it would be seldom watched...just used as explained above........As you can see by the questions I do need some advice from someone other than a salesman!.....

thanks and have a great xmas and new year