Vampire Ring Question

[Gorr_the_Gastly]

Ok so I am not sure of the formula of making a magic object so I am a little lost.

I need the prices for a ring of Protective Penumbra and a ring of Touch of the Sea.

PP is a 2nd level Sorc/Wiz spell list wizards get them at level 3.
TotS is a 1st level spell on the Sorc/Wiz Spell list.

[Diarmuid]

Are these intended to be always on or able to invoke the spell(s) x times per day?

In both scenarios, what Caster Level would the effect of either/both be at?

Item creation rules can be found in the DMG and in the online SRD.

[Gorr_the_Gastly]

The Touch of Sea would likely be Command word because he doesnt always need it.

The Protective Penumbra would need to likely be Use-Actived.

I looked up those charts and am I right on my math?
Touch of Sea (1800 GP)
Protective Penumbra (18,000 GP?)