worth enquiring if they will allow 1x business connection, and 1x residential connection
my compromise has been to have an expensive netgear VPN Firewall unit with 4x WAN connections that can be load balanced.
got the VM100 connection at the moment, but in the coming months will be also ordering an infinity connection.. then I can load balance between the 2.
Not usually advisable to shove any kind of computer in an attic space due to following considerations.
Cold in the winter
Hot in the summer
dust
I was going to sugest moving your superhub/modem + router up there, then run RJ45 cables down from there to wherever you need a connection, wireless should still work anyway if you use wireless
but... if any fault occurs, probably for health and safety reasons, engineers cannot enter an attic space. So should your superhub/modem need replacing you may have problems with that.