There are a bunch of special site mages that might fit the bill - Enchanters, Mages of the Metal Orders, Sorceresses, and the Cystal Mages like Taqwus mentioned. But they are pretty rare...
For summonables, the Lamia Queens (15 Nature gems, 7/16 have Astral) or Spectres (10 Death gems, 15/64 have Astral) work, and there's an equal chance for blood on either of them. Not too cheap and by themselves these mages are good at nether darts, but cheaper than a Coutyl!
Alternately, if you get a Mage with a random in Blood, you can cast Hellpower if you are feeling really risky
Blood however is a PITA since you have to keep them supplied with slaves. Blood magic in battles is pretty much more hassle than it is worth in 95%+ of the time (ok, except for a couple of late ones and Bind Heart!). I'd love a blood item that attracts slaves each turn to make this less of a micromanagement chore to do...
[ February 18, 2004, 15:59: Message edited by: geo981010 ]