Sadly, the Fr Leo Schafe site (analogion.gr/glt) doesn't have the audio; however, St Anthony's Monastery does.
Check out http://stanthonysmonastery.org/music/Wedding.htm
(in Byzantine or Staff notation).
- Processional Psalm - Verses are intoned, with 'Glory to You' being a short one (Eirmologic speed). The one I'm familiar with is 13 beats long (over 10 syllables), so they're done fairly briskly (like a troparion speed).
- The Alleluia should sound like an 'Alleluia' after the Epistle in the Liturgy - not drawn out at all.
Hope this helps!