what is the best option for one button controlled all HT?

If you get a light switch with remote control capability the harmony should be able to be programmed to transmit the infrared control code.  I did it 10 years ago.

Control4, Crestron, and Savant are three of the big home automation software and hardware brands. There are other more DIY-oriented solutions, but for a turnkey type of solution where you don't need to play around with things yourself too much, your best bet is to go with a local custom installer. They should have an agreement with at least one of those companies, and can get everything set up for you. It will cost some money.

I’d buy a bunch of smart bulbs and a good programmable remote. Yeah it might take two button presses, but how much you willing to pay to eliminate just one push of a button?