I used to mine till more than an year ago, so take my advice accordingly.
Firstly, I don't think that this much investment is profitable for mining bitcoins in particular.
Secondly, my suggestion is to get good graphic card and mine altcoins.
My strategy was to mine every new coin for 2 days to upto a month depending on how its launch goes, then I used to dump them and I "always" made profits.
Last suggestion, a big suggestion, would be to collaborate with others, display your mining management skills & profit and then do a group-buy crowdfunding. Then you'd be able to raise money and play into bigger risks and that would attract investors who are not into cryptocurrency as well.
Well I agree with early coin mining part, we have made huge profits, ROI is not the way to look into mining.
You need to find right coin at right time, online profit calculators will not give you best coins.
You need to be active and hunting on regular bases.
Or just put rig and use nicehash and dont touch it, for peaceful low return mining.
