Yes, iPhone 8 does have the stereo speakers.
Yes, you can record 4K videos with iPhone 8.
Yes, Apple iPhone 8 does have the VoLTE support.
Yes, iPhone 8 does have the OTG support.
We are extremely sorry to inform you that we do not ship the products outside India. Further, we also suggest you buy it from Singapore only so that you can get the warranty for the product. Only Apple iPhone X comes with the international warranty.
No longer the gold standard, the iPhone 8 is still all the phone you need.