Sadly, Boeing never took the 757/767 design of ILS tuning to 737, so you have only two receivers available for manual tuning.
With NG, you should have GPS and thus you can more or less consider zero map shift, so both FIX page and ND should be very accurate, so together with VNAV deviaton indication you should have a very good idea whether you are capturing the correct glideslope or not.