If you are in the UK I would suggest the Gong Pro 8", 450g for a 185cm one, and 170 GBP for a top quality 100% carbon paddle.
www.gong-galaxy.com/en/product/gong-paddle-carbon-pro-8/Its shaft has for me just enough flex to be paddling hours without strain on the joints (it has a round shaft to provide more flex than an oval one), and the blade shape is very fluid so you do not waste energy with fancy gimmicks on the blade that create turbulences when pushing/pulling it into the water.
8" (100 sqin) can be better than 7" if you like power and paddle with a low frequency.
Although 7" will be lighter, and you may get used to it if you just learn to perfect your catch to anchor a bit more the blade before applying power... so both options are valid. I reckon most people of your weight prefer the 7", though.
This model was originally made only for surfing, with another model available for racing, but people found out they ended up using the surfing model in flat water too, so the race model was discontinued.
Disclaimer: I am a Gong ambassador.