That is quite a bit of cash to put into cryptos IMO. I don't think you can go wrong with the top 2 in total marketcap.
Spreading it out within the top 10 or 15 with more weight towards the top would be a good diversification. (May want to leave ripple out)
Scaling in would also be a good plan.
I agree that spreading it out between top 10-15 cryptos would probably be the safest route. Maybe keep a bigger chunk in BTC and ETH and then an even spread.