The digital meter will cost you a lot more without giving you any more functionality for your application, which is calibrating your sound system with Avia or Video Essentials. I think I paid about $30 US for my Rat Shack analog in 1997 and I've never had a problem with it through four changes of residence and numerous interim tweaks.
the Radio Shack for about $40 US is what most of us use.
It is NOT the most accurate/calibrated unit. You can spend upwards of $200+ for higher end units that come with calibration curves - but you dont need this.
You really dont care that the inexpensive RS unit is +/- 10%. As long as it measures the volume the same for all 5 of your speakers - it's a great reference.