Dataset Needed – S&P 500 Constituents With Daily Prices

I want to run backtests on a momentum investing strategy.

So I’m looking for a dataset with a daily list of S&P 500 constituencies, their price for each day, and any possible events (such stock splits or company merger/splits). I bought this dataset in 2014 for $49 (1963-2014) but the company that sold the data to me is no longer in business.

Preferably usable in node.js, Python is a bit rusty.