For minute-level historical options data, several platforms offer accessible solutions depending on your needs for cost, resolution, and format. 

QuantConnt: Offers free minute-level historical options data for thousands of securities, including SPY, accessible via Python or C# APIs using the GetOptionHistory method.  This is ideal for algorithmic backtesting and live trading integration.
Massive.com: Provides free minute-level options data for a couple of years, exportable as CSV files for easy spreadsheet import or via API. This is noted for being user-friendly for individual traders compared to institutional-grade sources. 
suggestions to quantconnect - evt. add Quantpedia and PaperswithBackTest for strategies.