I did my downstairs my hdb.. book the place with town council, food catering, order some tables and chairs, got air coolers done. All under 850. Simple and convenient. If you have budget, hotel ballroom, SAFRA, chalet. Or even your friend or relative condo function hall. Personal peference, keep it simple, the lesser people you hassle the better. Cos will have favours to pay back next time also. :p
I am holding it at Treehouse Villa chalet . I will prefer to hold it in a condo function room and i like to have the idea of someone's house nearby for emergencies. For 150 pax you can consider Aquarius Cove, hotel function room. I have heard good reviews of this restaurant called Quentin's The Eurasian restaurant . They have a play area too.