hey michael -- go for it! i love enchantments too.
a few caveats:
-a big offensive aura theme is a tough sell; it was a complaint i heard often about GTC limited -- these cards (madcap skills, holy mantle, gift of orzhova) create games where you either stick the threat and win, or lose your dude and get blown out. it's sad for me to type this, as armadillo cloak brings back cherished childhood memories of playing two colors for the first time. that being said i just drafted triple rise and remembered how much i loved umbras; they solved both ends of the issue by printing totem armor and then making the buffs less efficient. i'm not sure how the umbras would stack up in the higher power level of cube, but i am a fan of rancor and angelic destiny!
-i doubt prison decks would be too powerful, as control doesn't care all that much and mid-range can often find answers and aggro can just attack. i'd encourage you to try ghostly prison.
-stay away from zur, my cube has a gazillion fixers and more than enough targets for the guy but god was he awkward to cast. the other lesson from zur is that 'bullets' are rarely worthwhile inclusions -- they're more of a constructed thing, i think, as playing with really situational cards is not to my playgroup's taste.
-(the big one) you gotta look at themes in the big picture sense. in order to add a theme you gotta weaken some other theme. the bigger the theme, the more it has to jive with the rest of the cube, since other decks need to want some of the theme cards and they also need to have more answers to the theme cards. in addition to being flexible, the theme also has to be powerful. i thought zur was worth trying since he needed no support. while this was true, though, he fatally suffered from a case of sucking, which made him no fun to play with.
synergy with the rest of the cube is a big point for me (poison principle!) so let me expand further with some concrete examples. if you have burning vengeance or chronic flooding, you need a big graveyard theme too. if you have enchantress effects, you need your enchantment theme to be enormous, as the enchantresses will not stand on their own and must have their inclusion justified by the rest of the cube. per the poison principle i'd actually discourage you from running enchantress effects and encourage you to find a lot of enchantments that could go in other decks.
card suggestions (just a place to start):
standard tutors: enlightened tutor, demonic tutor, vampiric tutor
fun enchantment tutors: idyllic tutor, academy rector, sterling grove, auratouched mage, sovereigns of lost alara, three dreams
some of my favorite enchantments: survival of the fittest, utopia sprawl, Angelic Destiny, Animate Dead, Assemble the Legion, Bitterblossom, Bloodchief Ascension, Detention Sphere, Faith's Fetters, Oblivion Ring, Pernicious Deed, Prison Term, Rancor, Sulfuric Vortex, Survival of the Fittest, Utopia Sprawl
some others i've tried: phyrexian arena, oversold cemetery, tortured existence, ghostly prison, eldrazi conscription, armadillo cloak, gift of orzhova, treachery, control magic, threads of disloyalty, honor of the pure, marshal's anthem, glorious anthem, gaea's anthem, mirari's wake, form of the dragon
avoid: recurring nightmare, no mercy, enduring ideal
answers: all the standard stuff like vindicate, pulse, decay, mortify, wickerbough, qpm. if the theme is decently-sized you have to start including stuff like duergar hedge-mage. if the theme is gigantic, it's time to dig deep!! nantuko vigilante!! esper charm!!
let us know how it goes!