Acers don't allow for overclocking as they use lockdown OEM motherboards.
http://support.acer.com/product/default.aspx?modelId=2219
According to them your motherboard supports ..
AMD Phenom™ II X4 quad-core processor (up to 3.40 GHz, 6 MB L3 cache, 2 MB L@ cache, 512 KB L1 cache)
AMD Phenom™ II X3 triple-core processor (up to 3 GHz, 6 MB L3 cache, 1.5 MB L2 cache, 384 KB L1 cache)
AMD Athlon™ II X4 quad-core processor (up to 3 GHz, 2 MB L2 cache, 512 KB L1 cache)
AMD Athlon™ II X3 triple-core processor (up to 3.1 GHz, 1.5 MB L2 cache, 384 KB L1 cache)
AMD Athlon™ II X2 dual-core processor (up to 3.2 GHz, 2 MB L2 cache, 256 KB L1 cache)
Although the latest BIOS P01.B3 now supports X6 CPU's.
While the recommended GPU probably based on what the factory fitted PSU can handle ..
NVIDIA® GeForce® 9200 Graphics
NVIDIA® GeForce® GT 320 with 1024 MB of dedicated DDR3 VRAM, supporting NVIDIA® CUDA™, PhysX™, PureVideo® HD technology, OpenEXR High Dynamic-Range (HDR) technology, Shader Model 4.1, Microsoft® DirectX® 10.1, OpenGL® 2.1, OpenCL™ 1.0
NVIDIA® GeForce® 315 with 512 MB of dedicated DDR3 VRAM, supporting NVIDIA® CUDA™, PhysX™, PureVideo® HD technology, OpenEXR High Dynamic-Range (HDR) technology, Shader Model 4.1, Microsoft® DirectX® 10.1, OpenGL® 2.1, OpenCL™ 1.0
NVIDIA® GeForce® 310 with 512 MB of dedicated DDR2 VRAM, supporting NVIDIA® CUDA™, PhysX™, PureVideo® HD technology, OpenEXR High Dynamic-Range (HDR) technology, Shader Model 4.1, Microsoft® DirectX® 10.1, OpenGL® 3.1 OpenCL™ 1.0
ATI Radeon™ HD 5570 with 1024 MB of dedicated GDDR5 VRAM, supporting Unified Video Decoder (UVD), OpenEXR High Dynamic-Range (HDR) technology, Shader Model 5.0, Microsoft® DirectX® 11, OpenGL® 3.2, OpenCL™ 1.0
ATI Radeon™ HD 5450 with 512 MB of dedicated DDR3 VRAM, supporting Unified Video Decoder (UVD), OpenEXR High Dynamic-Range (HDR) technology, Shader Model 5.0, Microsoft® DirectX® 11, OpenGL® 3.2, OpenCL™ 1.0