In Wine there is no good way to get access to the framebuffer. The easiest way is just to create screenshots from the X11 side (there are various ways for that). Regarding GPA what exactly does it do? I haven't used it, but is it something similar to Nvidia PerfSDK / PerfHud which provide you with performance counters and other nice debug mechanisms? Further in case you didn't know you can just run WineD3D and our d3d9.dll on Windows which can allow you to use the same flow on Windows and all the Windows tools. It might be useful as well.
