PW Productions@
it's funny, i recently had to explain the same issue someone was having regarding the eyes, it sounds to me like you are importing a set or a single sphere which you have already made, this is fine and what i'd recommend as zbrush's spheres are far too high poly for external use, and you can always subdivide your low poly eye. when you import an object in zbrush the imported object replaces your active object/ subtool. to stop this from happening its as simple as selecting an unused object from the tool palette and then you simply
append the imported object to the model that you want it used on, this is done from the subtool palette where you'll see an append feature.
constructing a body from the head is another matter entirely, its not quite as simple as sculpting from the neck as you quite quickly run out of polies. what you need to do is recreate the general shape of the head (EDIT: forgot to mention that to ensure that the alignment is correct and the scale you should append a zsphere into the heads subtool palette and create the base from there so that you can much up certain features), from a base or using zspheres, and the shape that you want of the body encorporated into the zsphere structure, once this is done you'll have a 'base' for further sculpting, your next step would be transfering the details on the head onto the new mesh, to do this you'll need to append the head or the base as i've said before to either the head or the bases set of subtools, once this happens the drangon's head should be alligned correctly with the base, from here you need to check how many subdivisions the head has and then subdivide the base to match these subdivisions, 5 for 5 or 6 for 6 etc, then bring both your models to their lowest subdivision, and use the project all feature with the PA blur at 0. repeat this process for each subdivision until you reach your final subdivision, you may need to play around with the mean and dist features to get what you want. (for the details of the head to be projected onto the body you need to have the body selected when you use the projectALL feature)
this should cover everything, if you have any further issues with this let me know, and if you dont understand what i've said i recommend going onto the zclassroom on pixologics website as they have many video tutorials some of which cover what i have just covered. hope it helps
