I have Darklight Gloves and Breeches which is how I was able to get such high enhancing magic potency numbers. My gear I used was:
Wand of Tremors (Double-slotted VIT, total of +27)
Paragon's Crown (+10 VIT)
Felt Robe (Single-slotted, VIT+16) or Mage's Robe (VIT-10)
Darklight Gloves (+15 Enhancing)
Darklight Breeches (+5 Enhancing) or Felt Gaskins (VIT+4)
Mage's Pattens (VIT+3, +5 Enhancing) or Healer's Boots (Enhances Regen) for "with boots" regen testing
And for accessories:
Dated Sphene Choker
Amber Bracelets
Amber Ring x2
Dated Sphene Ring x2
Dated Heliodor Ring
Changed them around to get whatever Enhancement Magic Level I was trying to test.
Now of course I don't use all this gear when playing WHM normally, my normal gearset is
Chiran Zabran's Tempest
Healer's Circlet
Healer's Robe
Raptorskin Satchel Belt (Double slotted Enmity-, total of -12)
Darklight Gloves
Darklight Breeches
Healer's Boots
Blessed Earrings
Black Pearl Choker +1
Amber Bracelets +1
Blessed Ring
Turquoise Ring +1
With this gear set I have 304 MND, 213 VIT, 538 healing and 422 Enhancment.
Stacking VIT is only semi-viable. There are quite a few things out there now that give lots of Healing Potency + (like Blessed Ring, Chiran Zabran's Tempest) and with that much healing magic potency, they'll far outperform any VIT pieces you can put there. Arguably you could replace the Turquoise Ring with an Amber Ring depending on how much you want to put into Enhancing, but personally I prefer the 18 MND because it not only gives the healing magic potency, MND directly affects how much your cures hit for.
I settle on 422 enhancement because it's a nice level, your Regen is just over the poison damage in Vale so it completely counteracts it and you have recent turnovers for Protect's DEF and MDEF values.
The Darklight Gloves are definitely something that every WHM should want. That 15 enhancing magic potency is really nice for Regen. The breeches are arguable, you lose the 30 second recast reduction on Presence of Mind and 3 Healing magic potency, but I think the 100 MP and enhancement bonuses are worth it.
No WHM should ever use the Mage's pattens full time. Maybe for a protect macro, but the bonus that the AF boots give to regen is ridiculous, it's gonna take a LOT to make me want to unequip those.