I'm not sure whether to use this: Class 1 http://www.kanda.com/products/Sena/PARANI-ESD1000.html or Class 2 http://www.kanda.com/products/Sena/PARANI-ESD200.html I'm planning to use it in an elevator for a senior project and I would like some suggestions or advice on which to choose. The ESD1000 says that an antenna isn't included with or on the chip and it uses v2.0 + EDR. However, the ESD200 chip says that it has an on-board antenna and it uses v1.2. Is it necessary to have the antenna because I know the ESD1000 has the newer version of Bluetooth but the lack of antenna concerns me. Also, why is the ESD1000 cheaper than the ESD200?