If you have room for it, the bare (insulated) wire is easy and will work with plenty of margin with an RFM69H. Even detuned you'll be able to reach 150 feet with several walls in between.
u.fl works nicely on a MoteinoMega, but an R4 doesn't have the footprint for a u.fl. The u.fl with a pigtail to SMA & rubber ducky is what I use on all my gateways.
Felix shows a way to mount an SMA on an R4 but I haven't tried it. The post is somewhere on the forum - search for SMA would be my guess.
JoeLucid has done a LOT of testing so he can squeeze out about 257db link budget (or something close to this, I think
, but the only time I've really had an issue with a bare wire is when I tried to put a mote underground - that doesn't work so well...
Tom