If money was no problem and free power I would grab up all the Equihash, Ethash and maybe some SHA-256 asics I could (used) along with RX 580 and Nvidia 1070 cards I could. Used or cheap New. (shop around). Your power (electricity) might be free but your power supplies wont be. Remember that when choosing a GPU setup. To keep costs down and actual number of rigs down to I would go with the ASUS B250 Mining Expert m\b and hookup 13 GPU's to it. Min of 16gb (2x8gb sticks) of ram, min G4400 CPU, 120gb ssd and you should be golden. Its the setup I use for my 3 rigs. Spare Parts, Spare Parts! Downtime costs you $$$.