Yes, the SWM 32 can a duplexer built in. You would need a 4 way splitter to geed the 4 OTA inputs on the SWM32. Depending on how long the runs are, you may or may not need an amp.
If you want the OTA stations included on the DIRECTV® guide, you will need 25 AM21 OTA accusatory tuner, one per box, otherwise you can connect directly to TV, but you will have to change the inout every time you want to watch OTA