The ATI Radeon HD 6350 supports dual monitors with the required DMS-59 adapter, you can find them here. This is a half height PCI Express card with 512MB of DDR3 VRAM.
Dell Part Number: HFKYC, 1CX3M
While were not using these for gaming, we are using them for dual monitors in a Windows 10 work environment and they work very well.
Discount Electronics' support is also outstanding and helped us find these products to replace non-Windows 10 compliant graphics cards.