In data center application, 40G QSFP+ transceivers with MPO connector and 10G SFP+ transceivers with LC connectors are most common transceivers. But, with two different connectors, how can we make a connection between these transceivers? And how long the distance the network connection can possibly reach?
You need a breakout cable - MPO to 8x LC. The reach of the cable depends on the PHY that is used, e.g. 400 m for 10GBASE-SR over OM4, or 10 km for 10GBASE-LR over OS2.
Make sure that the transceivers on each end support matching PHYs, that the QSFP+ port supports breakout in your scenario, and that you match the breakout/patch cable type to the fiber type.
Of course, you can alternatively use a DAC breakout - go directly from QSFP+ to 4x SFP+.
Product recommendations are off-topic here, I'm afraid.