You want not just POS coin but also a fully decentralised, meaning lots of validators where anyone can validate transactions, not just a few select.
NXT has it all. 100% POS, currently on average
2 transactions per minute,
220 validators/nodes,
746 peers.
Could process 200 per minute but blockchain would become 50 gb after 1 year.
NXT 2.0, that is in the works, will be able to process 200 per minute while only becoming
600 MB after 1 year.
It is estimated to be finished in 1 year, since by then blockchain can be 100 gb I estmate NXT will be able to process 3000 per minute comfortably.