could anyone recommend a good server machine to use to host two 150 slot servers from home.

and what sort of firewall i would need to put in place to do so.

utility bills and internet is not a problem just that i would like some info on what machines people are using to host from home.

You need:
16 GB RAM
E5-2690v2(3.0Ghz) x 3 cores
50 GB Disk Space

 

Merged post

Its minimal what you need to have. As soft i can recommend you Wireshark and other network tools

so i need three     E5-2690v2(3.0Ghz) ?

Its my recommended params, from my experience 

what internet speed would be a minimum required would you say ? upload and download i appreciate you answering me.

as best as its possible

You can always open any hosting website and look at their 150 players hardware information