As others have said, I would strongly suggest buying the plane you want for your mission now.
You are a new pilot and will need an airplane for training and flying. Building an airplane takes 3-10+ years for most of us who have a day job and aren't professional mechanics. So you won't have an RV-10 that you've built yourself anytime soon. If you'd like to build a plane, go to the EAA workshop on building a Vans RV and try pounding some rivets. If you like that, buy the empennage kit and some tools for < $5k and build that. If you are still having fun, buy the wing kit and flush out your tools for < $15k and enjoy the build. Several years from now, you'll need to put out the big money for the engine and avionics, and can sell your existing plane if necessary to fund that purchase.
In the meantime, decide whether to buy the RV-10 or an A36 or something else like a Cessna 182 to finish your PPL, earn your instrument rating, and start flying for fun and business. Folks have done their PPL in all three of these planes, but many of us are tough on our planes as we are learning, and a trainer is more forgiving and cheaper to repair.
I used to own an A36 Bonanza until I lost it in a divorce. It was the best plane I've ever flown. I have three kids, so a 4-seater was not an option for a family airplane. I loved the big back doors for loading, and it could carry a great deal and fly a long distance in comfort. I had a 1977 Bonanza, which was just as good as the 1990s models in my opinion except raising my gear took an extra second, and much better useful load and upgradability than the current G36. You can buy an excellent pre 1980 A36 for under $200k. Watch Beechtalk ads for a while.
Now I'm building an RV-7A with my oldest son. We've learned a ton and had a lot of fun. It will be fun flying with him, but it is not a family airplane. I will save money on maintaining the plane myself, but it is time consuming.
I am an electrical engineer and would not have been qualified to do significant maintenance on an RV that somebody else built, so I wouldn't have saved much money doing my own work on an RV that I built instead of bought. If you were an A&P with lots of experience, it would be a different story. Given your hefty airplane budget, you can probably afford to take your airplane to the shop anyway.
If money is no object, go for the nice glass panel. I'm putting in an incredible panel on the RV-7A because it is so much cheaper than in the certified world. But you can fly modern IFR very well with an IFR GPS, ADSB in/out, an engine monitor, a decent autopilot, steam gauges, and an iPad mounted on the yoke. There are lots of planes with this setup for under $200k.
Don't expect to be able to fly dependably for business in any single-engine piston plane. You'll need a backup plan to drive or fly commercial if it is cloudy and the freezing level is below your minimum enroute altitude. Without an instrument rating, you will need the backup plan anytime it is cloudy. You also don't know yet what you don't know and will need to be particularly cautious for several hundred hours as you build experience. It's easy to kill yourself and your family in a high performance plane when the plane's abilities exceed your skill. Kennedy is a good example. I scrapped a winter cross-country flight with my kids in the Bonanza one day because of weather, and learned another pilot in a much fancier plane with much less experience died that day on the same route as he picked up ice in the flight levels. His kids were screaming in the background as he was calling ATC. Even if you have a very nice plane now, you'll want to limit your flights for the next few years to those you could safely do in a basic trainer. If you eventually want to fly reliably for business, you'll need plenty of experience to be insurable as you move up to a FIKI twin or a turbine.
If I were in your shoes, I'd buy something that is convenient for training, easy to resell, and will meet 90% of your mission. If four seats is enough, a Cessna 182 is a good candidate. Look at the Cirrus too; I have 30 hours in one and don't like it nearly as much as the Bonanza, but many people do like them. Three years from now, you'll have your instrument rating, several hundred hours of experience, and a much better sense of what your mission is and what aircraft you need for that mission. If your first plane doesn't meet that mission, sell it and buy something higher performance to fly until you finish building your dream RV-10 or decide you need something else.
Best wishes,
David