I'd avoid overflight of DR Congo. Great Circle takes you over it, but I'd route East and come in to Kigali routing over Entebbe. I would also list Entebbe as your alternate. DR Congo has no radar coverage, no suitable emergency airports and very large mountains you need to descend over entering Rwandan airspace. There aren't even any night airports, other than Kinshasa. Goma is not safe, nor suitable for a business jet. You might get other opinions, but I'd personally burn a bit more fuel and route over Uganda. Easier and SAFER.
Just a humble opinion from a fellow aviator who has flown extensively in, around and to the locations you have listed.
EDIT: You'll love Kigali. It is a beautiful place. Clean, orderly and a temperate climate. Enjoy!