I'm doing something similar to my new Timberline TH60PC. I'm will be installing Dazzos a set for each set of strings. I will be coming out with a stereo end jack and feeding that into a dual preamp Sunnaudio MS-2 so I can equalize both channels separately. My end goal after research was to have minimal stuff inside the guitar, the ability to have separate EQ, single end jack and wireless. I'm giving up wireless with this solution.
Talking with Teddy from Dazzos, he said Harp Guitars are different because the strings to the outer edge of the top will have less vibration than the strings closer to the middle. because of this and he being a perfectionist, he will manually position the pickups before permanently installing them to get the best sound. I will be having him installing the Dazzos pickups.
I know some have just wired KKs together to create a mono output, but that changes the output impedance. Sunnaudio has a internally blending preamp that you could use to keep the impedance the same, but you lose the ability to EQ the two sets of strings separately and you have a battery and other stuff inside the guitar.
If you search on the web there are many ways people are using pickups, and you can have paralysis by analysis.
Good luck with your research and final decision. Congrats on your new HG!