Here is the MFG support page listing that motherboards features, system compatability references, notes on CPU support etc...
Quote Originally Posted by http://www.asrock.com/mb/overview.asp?Model=AM2NF3-VSTA&s=
- Socket AM2 for AMD Phenom™ X4* / X2, Athlon 64FX / 64X2 / X2 / 64 and Sempron processors
- Supports AMD's Cool 'n' Quiet Technology
- Supports Untied Overclocking Technology
- Supports Hyper-Transport Technology

*If you adopt AMD Phenom™ X4 AM2+ CPU on this motherboard with AGP VGA cards, please click here for AGP VGA Card support list.

**If you use AM2+ CPU on AM2 chipset motherboard, the system bus speed will downgrade from HT3.0 (5200 MT/s) to HT1.0 (2000 MT/s), but the CPU frequency will not be influenced
AM2NF3-VSTA CPU SUPPORT LIST

Reading through the downloads and bios revision notes, I don't see anything covering specific graphics cards. AM2NF3-VSTA DOWNLOADS

A quick glance at the AM2NF3-VSTA OVERVIEW shows that it has one 8x agp slot. Your graphics card selection is going to be limmited to an 8x AGP graphics card, or PCI, not to be confused with PCI-E. Preference should go to an AGP graphics card, and weather or not you can get AGP graphics card drivers for your opperating system.

Besides needing an adequate power supply, and being on the "phenom" VGA compatability list, and needing card specific drivers for your OS, the two cards that you listed, should work with your motherboard. I couldn't find any specific info on the AGP port's Voltage support. You need to know if it's 1.5 volts or 3.3 volts or both, and it DOES matter. Some AGP graphics cards do not support one or the other and may cause damage to the board and the graphics card or any other component that's fitted when you power it on.. That is if the graphics card physically fits in the slot, but is not compatible with the motherboard voltage wise.