DarkJester said:Orange Ioun Stone: +1 Caster Level
Create Magic Tattoo (Spell, Spell Compendium): +1 Caster level
Does sanctum spell give you a +1 caster level? I can't remember.
Brain said:If you're arcane - ring of arcane might from complete arcane
if you're divine - prayer beads
pawsplay said:Okay, the OP confuses me. You want 8th level spells at 11th level? Use a scroll or other item.
from SRD:
[B]Create Undead[/B]
Necromancy [Evil]
[B]Level:[/B] Clr 6, Death 6, Evil 6, Sor/Wiz 6
[B]Components:[/B] V, S, M
[B]Casting Time:[/B] 1 hour
[B]Range:[/B] Close (25 ft. + 5 ft./2 levels)
[B]Target:[/B] One corpse
[B]Duration:[/B] Instantaneous
[B]Saving Throw:[/B] None
[B]Spell Resistance:[/B] No
A much more potent spell than animate dead, this evil spell allows you to create more powerful sorts of undead: ghouls, ghasts, mummies, and mohrgs. The type or types of undead you can create is based on your caster level, as shown on the table below.
Caster Level Undead Created
11th or lower Ghoul
12th–14th Ghast
15th–17th Mummy
18th or higher Mohrg
You may create less powerful undead than your level would allow if you choose. Created undead are not automatically under the control of their animator. If you are capable of commanding undead, you may attempt to command the undead creature as it forms.
This spell must be cast at night.
[I]Material Component:[/I] A clay pot filled with grave dirt and another filled with brackish water. The spell must be cast on a dead body. You must place a black onyx gem worth at least 50 gp per HD of the undead to be created into the mouth or eye socket of each corpse. The magic of the spell turns these gems into worthless shells.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.