Trying to connect 1GBASE-LX to Netgate XG-7100 with Intel X553 SFP+ - is this possible?

So we are setting up a test lab in a data-centre, and I'm learning all this stuff trial-by-fire...lol.

The datacenter provides internet connectivity via 1G LX (Single Mode). So my plan was to source 1GBASE-LX SFP modules.

For the router, we are ordering Netgate XG-7100's, which have two in-built SFP+ ports.

It also has a PCIe slot - so I thought I could add additional ones if needed via an Intel X520-DA2.

However, I've been told that the XG-7100 won't take SFP+ cards, due to insufficient cooling/power.

Furthermore, apparently the in-built Intel X553 SFP+ ports do not take SFP modules =(.

What are our options here?

Should we bite the bullet, and get media converters? Or is this a SFP+ module that will work with 1G LX?