The choice of AD9910 and AD9858

[Toise]

Hi, there.
I want to start a project that requires a 10MHz-310MHz chirp signal. The AD9910 and AD985858 high-performance chips have a chirp mode, and the output signal frequency can reach 400MHz, which meets the design needs.
AD9858:
Two outputs;
High power consumption (2W);
An external clock circuit is required to generate a 1GHz clock signal
AD9910:
One output
The power consumption is relatively small;
No external clock circuit is required;
The design needs to consider the size and power consumption of the circuit board, and the DDS needs to provide two output signals with equal phases. If you use AD9910, you need to use a power divider to split the output signal, and use AD9858 to save the power divider; but AD9858 requires an external clock circuit, which increases the complexity and difficulty of the design; in addition, the AD9858 power consumption is 2W and how big is the AD9910?
Here is the parameters article of AD9910 for your reference.
https://www.utmel.com/components/ad9910-digital-synthesizer-datasheet-schematic-and-pinout?id=260
Wait for help to analyze it.
Thanks a lot.