Does anyone know what the green right angle 2 pin plugs on the mighty board motherboard are called I’m trying to get hold of one or get hold of something that can be used instead. I want to install additional cooling but with out this plug in can see it being problematic

I never understood the reasoning for such connectors, as I personally never really constantly re- and disconnect them, and as the additional connections pose some extra, avoidable failure points.
I’ve replaced the connectors on my RAMPS with 20A capable normal screw terminals, just for safety, but any >5A rated terminal will do fine for everything, EXCEPT heatbed connectors!!

That said, the green part you are looking for is, for all I can tell, a "RND 205-00177_"_ (Vendor’s part number) from RND Connect
It’s a standard-looking connector, but so far I could only find it on a few electronics websites, my favorite being this one:
http://www.reichelt.de/RND-connect/RND-205-00089/3/index.html?ACTION=3&LA=2&ARTICLE=170354

However it miiight not be viable to buy this little part together with shipping, so maybe replacing the terminal block with a standard screw terminal could be an option, too.