The regular RFM69 has much better range than the NRF so you might not need the high power version at all. It does require you buy/build your own antenna though. I'm using the 915 MHz version and can cover my whole house, yard, and garage with a small helical antenna I bought on ebay (the NRF couldn't do that even with an external antenna). Just search for "XXX hz helical antenna) on ebay to see a lot of options.