UPDATE:

What are the best provider for historical data?

That support ..
OHLCV
Websockets
Order Book
etc

I already search many of them such as nomics , shrimpy ,  coinmarketcap , wyre , coincap , coinapi.io , coingecko , kaiko(din't check yet)
But most of them are not perfect or either very expensive, no websockets, no OHLCV 

While for real time data, do you think is it possible to use CCXT?
Even though most of people are only use CCXT for bot or data analyst

Never heard anyone use CCXT to make coin aggregate website like CMC or other coin index does.

If anyone can help me finding the best solution and idea for both problem.
I'll give you $100 worth of BTC

Thanks.