er...hum.
Oh,well.
The 3d scanner solution is cool if you have an amazing budget (in case there's any) for your projects. And that counting you bought the right one.
I prefer to model by hand
If you have the skills (I have 'em

) , you can do the workflow which inho makes more sense: Model in an amazing organic modeler (I am considering we're taling bout characters, buildings have a dozen other workflows and tricks) , like Wings3d, Silo, Max 9, Maya, for the base simple model, that is, the 5,000 tris model. Imho you still need one of those for that accurate modelling, imo, not as fast and not same cntrol to do this Zbrush, but is doable with it too. Your wings3d(or whatever) mesh, you can now Uv map it. Once you have this, you can build from that base mesh , a crazily heavily detailed mesh, with wrinkles, scratches, loads of mesh detail, etc, in Zbrush , or Mudbox. And indeed, these days you could also do it with Blender sculpt mode. Or Silo 2. You can then, use a tool like melody, but there are others (for those not having shader 2.0 card) like orb, ATI normal mapper, and several others, that will allow to generate, from the high res mesh version, a baked bitmap (ie: a tga) , with certain charcateristics (a normal map, is like a 3 color gradients representation on how lights atack that volume, I think ) , that is applied to the original mesh of 5,000 tris. The generation of the normal maps, yep, could also be done by blender, but I think 2.43 did only have yet support for flat surfaces normals maps only...Of course, you can allways do the hi resh details in Blender, and use an external tool liker orb, to generate th normal map tga.
The engine, if has support of normal maps , or parallax maps, will load that 5,000 tris mesh, looking like as if it were the 1 million tris version... (I forgot to explain the texture proccess, but that'd be a whole chapter ..as best result is also achieved adding also specular maps, and other channels, and as texturing and uvmapping is really complex for normal maps proccedures... )
I have a feel Mudbox has a better UI than Zbrush, and a hope that...Blender can be used if not now soon (i dunno) in an art pipeline to output crazy-res modelling details...
blender can bake everything into a bitmap, since recently.One of them is lighting, it can do lightmaps fairly well.