Will this motor https://www.proto-boards.com/product-page/190kv-electric-skateboard-motor-6374 from Protoboards be enough as a single motor or will i need 2. I am planning on using 2x8000mAh lipo batteries in series.
If you use 10-12s batteries it should be ok, but it depends on your weight and other conditions…
This motor is commonly used in many builds on this forum. I have personally used this on a single drive which worked out great. It is one of the biggest motors that is used for estates, so it will be perfectly fine. Because of the relatively low motor kv I would recommend that you use a 10s battery for extra speed. I dont have any experience with this reseller though.
8/10s and youll fly 
Okay nice, I only weigh about 51 kg and there are not too many hills here. so I should go with 2x 8000mAh 5s in series.
if you weigh just 51kg 6354 Motor would be enough for you, but if you want extra power, go with 6374