I could fit 10x 1TH/s miners plus a switch into a 42u rack but I have no idea if 8A (1.8KW) is enough power though 
Not even remote close to enough power. You would need 12-16kW with modern hashing hardware.
Agreed - 1.8kW is NOT enough for 2 miners
Yup, you need at least a 60A/208V circuit for a total of 12480W but most if not all DC's limit you to 80% of rated capacity so that gives you just under 10kW.