52 (epic) Monk with 52k - what to upgrade?

[remen]

Hi guys, I was hoping to get some advice from you expert monks out there on the best way to spend the extra plat I've got saved up on my 52 monk. He currently has epic, fungi, IFS, sash of the dragonborn, spider fur cloak and pretty standard stuff in the rest of the slots. I solo 90% of the time but don't mind grouping from time to time and was wondering what would get me the most bang for my buck with the extra 50k or so I saved up. The options I am considering are:

1) Tstaff - I have heard the stun proc is great for soloing
2) Haste Upgrade - Either the Seahorse belt for a 10% haste upgrade & stats or a CoCW + spider fur belt (slightly more haste but not as good stats)
3) Haste belt/Hiero Cloak - Get a less expensive haste upgrade like RBG or RBB and then use the extra plat to upgrade to a hiero cloak for a big stats boost
4) Other - is there some better item / combo of items to look to upgrade than the options I came up with?

All advice and feedback is much appreciated, thanks!