If you get the Bullet (wifi, not the camper!), be sure you get the lasest version!!! (I cannot stress this enough). The older versions have moisture leakage around the LED panel and tend to get zapped in bad weather (we have replaced over 25 of these due to this issue). Most brand-name retailers now stock the newer units, but beware of the eBay/Amazon listings. You can Band-Aid the older ones with sealer around the LED cover, but it blocks much of the LEDs.
That being said, we have the best omni-directional performance when paired with a D-Link antenna like this one (
click here).. Not only does it provide fairly good performance, it has a mounting bracket that is easily adapted for RV use. Fairly easy to disassemble for travel. Takes a bit of tweaking on the settings to get it to optimal performance, but for the advanced user, it shouldn't be much of an issue.