I think you were talking to a carnival salesman that had no clue as to what he was selling or the technology. HD satellite signals use the exact LNBFs as SD signals. There is not a HD LNBF or a SD LNBF.
If you buy a one cable solution LNBF, make sure that your receiver install menu selections support the OCS (One Cable Solution). If your receiver does not support OSC settings, transponders will double scan in Blind Scan mode as both horizontal and vertical polarities and incorrect transponder frequencies. Manually inputted frequencies will also need to be calculated due to the LO differences between horizontal and vertical transponders. C-band OCS LNBFs use one voltage and two LO frequencies to stack the horizontal and vertical transponders.
Never heard of a 200K noise temperature LNBF in this century. If so, this must be a typo or a tremendously crappy amplifier! Noise figures are only part of the specification when optimizing for best performance. Also, most noise temperature specifications are marketing lies. Look for actual lowest amplification noise, highest polarization isolation, lowest stability, flattest gain (variation across the band) and the lack of harmonics.