I'm a Horde guy so Scryers all the way. In the end, you'll probably find that the gear you can buy from both sides does not matter much as you'll find equivalent in instances. At least the blue stuff.
As for epics, both sides have something caster-oriented but the Scryers' ring would help you more than the Aldors' necklace.
And then as for the inscriptions, it's rather trivial, in my opinion. At least, it becomes trivial once you hit Exalted.
For example, as a Moonkin at Honored you'd be interested in:
Aldor - [Inscription of Discipline] +15 Spell Damage and Healing
Scryer - [Inscription of the Orb] +13 Spell Critical Strike Rating
So there's a pretty big difference as to whether you want more SpellDmg or SpellCrit.
However, once you hit Exalted you get to "choose" between:
Aldor - +18 Spell Damage and Healing & +10 Spell Critical Strike Rating
Scryer - +12 Spell Damage and Healing & +15 Spell Critical Strike Rating
At level 70, you need about 22 SpellCrit rating for 1% SpellCrit so there's a difference of about 0.25% SpellCrit and 6 SpellDmg which amounts to 6 more damage on a Starfire and even less on a Wrath or whatever... So they're both pretty much the same.
In conclusion, it doesn't matter which side you choose. :P (Unless you're an Alchemist in which case only Scryers have a
recipe)