We've had reasonable success with Intelix baluns. We haven't used this particular model, but the DIGI-VGA-F
looks like it would do what you want. From Intelix's literature, "The DIGI-VGA-F features up to
1920x1200 computer video performance and high-fidelity 20Hz to 20kHz audio performance extension up to
350 feet." (emphasis mine)
Based on your 175 feet, assuming you have a good quality CAT6 run and minimal electromagnetic interference, you should be able to push 1920x1200 at that distance. Intelix also says, "RGBHV video up to 1920x1200 at 250 feet down to 800x600 at 850 feet (Cat 6)."
You can get the DIGI-VGA-F here for $315
, the lowest I could find through a quick web search. I haven't done any trust checking on the seller/domain.
Hope that's helpful!