Hi Manu,
What is your output power requirement? Frequency coverage? Do you have a target price? Do you have LO phase coherency requirements?
Support for nuand's bladeRF was just recently pushed to gr-osmosdr for both GNU Radio 3.6 and 3.7. The output power is 6dBm CW, so with some backoff for linearity and PAPR on your transmission signal, you're probably at -6dBm or so for transmission. Harmonic filtering is required if you plan to hook it up to an antenna. The frequency coverage is from 300MHz - 3.8GHz and costs $420/board.
More information can be found here:
Feel free to e-mail me directly off list if you'd like to discuss more.
Brian
Full disclosure: I'm involved with nuand and bladeRF.