Mate, in Singapore there's a van club for modified vans, you can go look at their forum for inspiration : http://www.eurovanclub.com/
As for Hiace parts you can try this Taiwanese company : http://www.alibaba.com/company/10838933.html or look in ebay.com.sg cos there are helluva lot of Toyota Hiace roaming on Singapore roads.
cheers.
Philip