Goa is a good option.
But just sharing a point of concern. It is extremely important to be careful in selecting Hotels in Goa for International Conferences .There are many Hotels violating many coastal regulation zones and environmental laws .
2 years back Tehelka Think Fest  faced a similar trouble . 
http://www.deccanherald.com/content/202792/controversy-clouds-tehelka-thinkfest.html

~ regards
Anivar