For 64k ticket+misc expenses:
Istanbul: Not very expensive, ticket within your budget, awesome nightlife, no warm beaches tho esp in this weather. Plus jet lag'll take abt a week to come off...
Colombo: short and cheap airtravel, night life not v vibrant, more of a relaxing type affair.
Dunno abt Dubai/Emirates side never been there... if you wanna see the same Paki/Indian faces, lottsa shopping, night lights etc thn Emirates is the way to go.
Yes Kuala Lumpur is awesome too! Nightlife in and around KLCC (kualalumpur city center is amazing cafe hard rock etc)... find some cheap spot to stay and youre good to go. If you can further afford go to one of their Islands like Penang etc