Simple solution: move to OVH. Although they don't have servers in SE Asia, perhaps 100% uptime is more important than shaving 100ms off the ping time. (As far as I can tell they don't have real-time audio or video anyway).
What makes you think OVH could cope with a 200 Gbps DoS attack of this nature? A quick look at their services indicates they don't mention what kind of attacks they defend against, and SYN floods are some of the hardest to defend against.
SYN floods are pretty easy to defend against. Most devices do SYN cookies in hardware at line rate. We run midrange devices that have thwarted 40M PPS SYN floods without a problem. I'm not bragging or anything, just offering a datapoint that SYN floods are easy to stop.
Customer testimony on places like Webhosting Talk have cast all of those numbers into serious doubt. OVH is more likely to nullroute your IPs than it is to fight off a 300gig attack.
Do you have a ref for that? I did quite a few searches and didn't find a single person on webhostingtalk saying they had been null-routed by OVH in the past year. Only one guy who worked for a competing hosting provider.
OVH frequently has problems with false positives, or so some of their customers report. They may offer good value for non-critical services, but they aren't exactly known for 100% uptime.
I've been using them since March, and have had 100% uptime during that period. I haven't had any false positives, and the one time they did mitigate a DDoS I didn't even notice it. As I understand it you'll just have a slightly higher ping time when the DDoS is active. An occasional false positive with slightly higher ping time seems a better option than your site being guaranteed to get null-routed for 24 hours (as happened to me on iweb, although I managed to convince them to remove the null route after a few hours).