As far as requesting existing 3D assets to be liberated, Zone's own Requests forum is by far the best chance; everything nowadays in the pie rat world first appears here, by whatever method, and filters elsewhere.
Persia/Peers is geared almost entirely toward the software side of Media, and the few threads of assets that exist are limited to a handful of low-traffic generals that have been stewing for a decade or more. You will have basically zero luck requesting models in Persia.
As far as requesting original 3D content be created, there's plenty of places. All the major 3D brokerages are full of artists willing to take requests or reasonable commissions. On the flip side, you will have virtually zero luck requesting new mesh content here. Better luck exists with requesting conversions of existing mesh from one format to Daz (or other format).