I was also looking for sources of intraday data that covered a period of time, I came across the following sources
https://www.algoseek.com/: Intraday data back to 2007 for US Equities, Futures and Options. Intraday they have tick, 1 sec, 1 min and 5 min OHLC bars. Institutional data and well priced.
https://www.tickdata.com/ : Global Equities, Futures and Options. Intraday bar data from 2004. Consolidated tape since 1993. Have tick and bar data with 1 sec/1 min/5 min OHLC. Institutional quality data but very expensive.
https://www.barchart.com/ : Been collecting Futures data for 50+ years. Also have Options and some Equity. For Futures data they have a great reputation. Bloomberg : All the data you ever need BUT you are limited in the amount of intraday data you can export from your Bloomberg and upto about 250 days historically.
There are much more out there I haven't stated, but you can choose to try out on the above because they are the ones which are majorly used by most people.