x213a
No idea what the situation is where you are, but we were able t get a perfect picture on a laptop here in Belgium using a PC Card digital receiver (can't remember the make, it was on niece's laptop) using the stubby little antenna that came with the card, no need to connect it to a regular antenna.
Of course, if you can get a better antenna it will always work better but then you have the hassle of aligning it so it all depends on where you are and what the signal is like.
Oh, and as far as I can remember TV Licensing will not be an issue as your existing one will cover you for using the laptop as a portable TV on the move. It's when you use it permanently at somewhere other than your home that they get a bit sniffy.