Minimum Requirements of TV tuners is generally a P2 400Mhz Class System with 64 MB RAM, so there wont be any problems installing the tv-tuner in your PC. So the answer to your query is Yes, it is enough to run an internal tv-tuner on your PC. Also you can record clippings through internal tv tuners itself. External Tv tuners, what i guess you are referring to is USB based tv-tuners, but the performance is not the same as internal tv-tuners due to the bottlenect of Bandwidth from USB 2.0 Port. And more importantly since Yours is a 810e board, most probably its having a USB 1.1 port and the BW in it is far less to run a USB based tv-tuner. So you can safely remove the External ones from your option.