My boyfriend and I got engaged today and the wedding will be in March 2008.

Things I need help with:
1. My partner hasn'y bought an engagement ring as yet but we wanted it custom made and we have the design. Really worried about getting ripped off and have no idea where to go in Singapore. Can anyone suggest reputable places?
2. Has anyone married in Koh Sumai? I was thinking either Four Seasons Hotel in KS or antana resort & spa but was wondering if anyone had good/bad experiences there or they can recommend somewhere.
This is kind of urgent as we really want the ring before we go home in 4 weeks and as it will be custom made know we need time.
Please help me!!
Thanks