Clerics do get some Conjuration (creation) spells, but the ones I can find
aren't worth spending a feat to extend.
True name actually looks pretty good, especially if you were to go Malconvoker. Reducing the SR of the fiend you want to call or giving yourself a bonus to the opposed Charisma check might be worth a feat. (Unfortunately, this part seems broken. WoC is [Exalted], so you lose it if you commit an evil act. Planar binding
an evil creature is an evil act. So, presumably, is imprisoning a celestial and forcing it to work for you. I'd either drop the rule that casting an [Evil] spell is evil enough to make you lose [Exalted] feats, or rule that planar binding
never gets an alignment descriptor.)
All in all, it's not horrible, but not great. I'd definitely take it on a Conjurer, summoner Sorcerer or Archivist. Especially if I decided to be a Vow of Poverty Necropolitan Sorcerer/Malconvoker.