The best kind of armor for most IW Mesmers is the charlatan armor set.
This armor set gives 10 more armor when enchanted, which is pretty much all
the time for your character if you are IW.

IW mesmers like weapons that has the the 20% longer enchantment mod to prolong
the life of IW as well as those that come with an energy +5 Mod

Focii is common among IW mesmers to give sufficient energy to energy intensive
builds as well as give the half skill recharge mod for illusion magic spells
in able to make IW ready early in certain chances just in case.

I myself prefer a shield however when I use my build because of its high
attribute levels for Tactics and my concerns of defensive capabilities.
The shield I use of course is the one that gives 2 damage reduction and
45 Health while enchanted.