I would recommend against OSK -- you can search the forums on OSK previous projects e.g. You City and Pangaea, and expect to find several complaints about unfulfilled promises, poor management, unsatisfactory workmanship, etc.

Is there any large units fit for family in High Park? Approximately 1000 sqft unit?

Older apartments like Shang are larger, also freehold but I see many people letting go. Not sure if it is due to maintenance issue or occupants' problems. High Park is attractive due to the location, facilities and Gamuda. But for this kind of price, can one consider other options in PJ vicinity?

For own stay, RM900k can get you larger units in equally if not more attractive areas e.g. Sri Hartamas, Mont Kiara, Segambut, Bangsar South, etc.

Have you looked at Megah Rise in Taman Megah? Developed by PBB Hartabina...Robert Kuok's company.