When buying Phicen dolls, always go for the "Stainless Steel" version. The old versions before 2014 had plastic "skeleton" inside so they only had limited posability. The plastic skeletons also broke often. The stainless steel skeleton is a whole different world. You can smoothly pose the dolls in all sorts of ways and you won't really have to fear about breaking them.
Of course, extreme poses will probably cause damage, like overbending a joint to where it's not humanly possible in real life. As a general rule, if the joint of the Phicen doll reaches a point where it stops, do not attempt to go beyond it or you might damage it badly.
Another tip I have for you is that when you're first replacing the hands of a Phicen doll to use the other extra hands it comes with, use a hair dryer to heat up the current pair of hands attached to the doll to loosen them up. That's when you can safely pull them off. The reason why you need to loosen them up first is that they are very tight and if you pull the hands off of the ball joint that's connected to the wrist, you risk actually pulling the ball joint out of the stainless steel skeleton! That's no good and putting it back in is such a hassle. If you also somehow manage to pull out the ball joint, it will become loose and you won't be able to make the doll's hand hold poses properly anymore. It will become "wiggly".
As for buying clothes for your Phicen dolls to wear, ALWAYS wash them first with laundry detergent because sometimes, these clothes have excess dye and they might stain your Phicen doll badly. What I do is I handwash the clothes, squeeze, scrub until I see the excess dye go away. Next, I put the clothes in a tupperware, put some more laundry detergent in it, and then fill it up with water. I then leave it there for 2 days. This way, the clothes won't have excess dye anymore. Dry the clothes and then make a part of it touch a small area of your Phicen doll's skin to see if it would stain. Make different parts of the clothes touch the Phicen doll's skin just to make sure it's really safe to wear.
For maintenance, you might notice that your Phicen doll will get dirty over time. All you really need is a brush or even a tiny paint brush and you just brush the dirt away. Dirt on a Phicen doll tends to stick and the easiest way to get them off is by using a brush. Just a soft brush is ok, not too hard. When it comes to the doll's stickiness, you can make your Phicen doll feel smooth again by using the common Johnson's baby powder. You don't need a lot, dab your paint brush into a small amount of baby powder and brush your Phicen doll's body with it gently.
As for the types of available Phicen dolls, there are the standard stainless steel ones beginning from Phicen PLMB2014-S01. Most of these dolls come with headsculpts included. They are usually in the range of $80 to $110. The limited edition ones are more expensive, usually starting from $140 to $200. These are usually based on comic book characters like Shi, La Muerta, Mercy Dante, Red Sonja and others. The latest right now are the Phicen S16A Pale and the S17B Suntan body types. These two don't include headsculpts, only replaceable hands and feet, so be careful when buying these two models!
If you want to learn a little bit more about Phicen dolls, feel free to read my reviews of a couple of them
Phicen Shi Kireina Kimono Asia Version
Phicen Demon Huntress
Phicen PLMB2014-S02 Tan and Suntan
How to Keep Phicen Dolls Fresh and Clean