I think your best bet is to just experiment with the different figures you have available to you before you buy anything and see which one gets closest to what you are looking for. No one here can really tell you which figure you should be using, and everyone has their own opinions. G2 is native to DS, so it will work best in DS. Various people have problems with it working as intended in Poser even with DSON, while others don't have any issues at all, so it likely depends a lot on your system and what you're trying to do. 

You mentioned weight mapping. The only figures that are weight mapped in Poser are Rex and Roxie, and Alyson2 and Ryan2. There is a free version of a weightmapped V4 available somewhere - RDNA I think - but it stll requires purchasing V4 from DAZ if you don't already have her. Miki4, Tyler and Anastasia (both are morphs of Ryan2 and Alyson2) - those 3 have to be purchased separately. I think Tyler comes with Anastasia here in the MP. None of the other Poser figures are weight mapped, so you would need to do that yourself. And content is rather limited for all of them.