I'm working on a mod, and it will have a couple daedric temples. I was hopeing someone knows which daedra commonly serve Malacath, Namira and Sanguine, so I can place the proper daedra in there respective temples.

Also, since Sanguine doesn't have a temple in Morrowind, I was wondering if there a mod out there that has a statue of him, or if any of the existing statues look enough like him to use.

• For Malacath, the http://www.uesp.net/wiki/Morrowind:Ogrim#Ogrim are the only servants we have seen as far as I am aware. As for ideas to what to have, something orcish, I'd guess
  
• Nothing on Namira, but she is a nature prince of ugly, slimy, and dark things, so make up something that reflects that kind of nature. Remember, she's not an "evil" daedra, but the goth, icky cousin to Kynnareth. I know her realm is described to be nearly, if not, pitch black, with lots of skittering on the ground.
  
• Nothing on Sanguine either, but I'm going to assume they look as though they engage in hedonism, but I'd say nothing to the level of Slaanesh in Warhammer. As for statues of him, you could try to model a statue of what he looks like in http://www.uesp.net/wiki/Lore:Sanguine

NOTE: You may need to craft your own daedra and statues, but just remember what I posted above. As far as someone creating all those, no clue.

There is some possibility that the lesser Daedra associated with other Daedra Princes could serve them, such as how Mehrunes Dagon employed Seducers, Daedroths, Atronachs, and Spider Daedra. Yet they would not look exactly like their counterparts serving other Princes, they'd likely look altered depending on what Prince they served. Look at the difference between the Daedroths who served Mehrunes Dagon and the ones who served Molag Bal. Molag Bal's Daedroths were slender, green, with humanoid bodies and using poison and electricity. Mehrunes Dagon's Daedroths were huge, tan (like the Clannfears and Scamps), with monstrous bodies and using claws, teeth, and fire. Likewise, his Spider Daedra had exoskeletons that resembled the armor of the Dremora.

Atronachs, however, may be an exception as either their elemental makeups necessitate certain forms or just because they don't seem to tie themselves down to any one Prince.

Would I need a 3d modeler for that? I've never used one, nor do I have one, but I'm willing to give it a try if I can get my hands on one.

You will need a 3d modeler if you want to make new meshes. SInce animations are hard to make, think about what animations already in morrowind you want to use for any new creatures, since the mesh is going to need to be able to avoid clipping when executing the animation.