Oddly enough, I've been helping a friend with a Naga mage lately so I've been giving this topic a lot of thought.
Naga's aren't that bad of a mage choice as sapient critters go. They're no pixies, but they aren't centaurs either. They get a decent amount of attribute boosts, and have above average charisma/willpower/reaction. Thus you can grab Charisma 6 and Willpower 6 and get +2 dice to resist drain than a human mage. You also get +2 body and enough strength. You only have a 4(6) agility so you're never going to be that sneaky. That combined with no hands, means you really want to rely on your spells. You can grab Influence 1 (or intimidate) and roll 7 dice base which makes you a reasonably friendly/scary talking snake.
You should keep in mind that nagas are big, not Titanoboa big, but big. As a 10 meter long snake, you've got 2 meters on
this guy. You could very well look like
this drawing of a 10m Gigantophis. Nagas are venomous so they might be thinner than the above snakes due to lack of muscles needed for constriction.
You can milk yourself once an hour and make a 800Y toxin. That means you could easily make 80-240Y an hour which is pretty sweet for downtime work. However, I expect most GMs won't let you do this so I wouldn't count on it.
Can they wear armour by the way?
As for naga armor, there's two ways to look at it. One way is to follow the shadowtalk in
Running Wild page 45 that says nagas can't wear armor. The other is "I paid extra for this armor so it works somehow" which is the approach implied in
Runner's Companion. Personally I'm in the latter camp.
Large snakes move pretty smoothly (seen
here and
here) so you likely could armor the backs pretty easily or with a thin enough armor. Armor plates with gecko tape along the back should be work. Heck, you likely could make a little "cape" of ballistic fibers tied at the head and tail and that'll cover a large area. So I could see modified armor vests or armor jackets working. Second Skin or FFBA might be thin enough to protect the undersides without too much trouble. Modified helmets should also work. I wouldn't allow SecureTech PPP Shin Guards though.