Serendipidously your wish is about to be launched, it's smaller than the XRF, has 2x3 standard pin header in a line, is tollerant of 5v data. Has onboard voltage reg so you can power it from even higher voltages if desired. We have emulated the FTDI cable layout so in many respects it can be treated like a 1/2Km long cable. DTR is also there so if your micro supports it you can reset and program wirelessly many platforms like the thing was connected by a wire, there's videos of an XRF doing the same on you tube.
The new URF and ERF both utilise the new Johanson ETSI balun and associated chip antenna, this is whats holding up release, they are still on back order. This will mean the performance of the two at 315/433 will be very limited compared to the XRF but deliver ETSI compliance. Something I'm sure hippy will be pleased of.