Budget makes a difference. I was going to suggest Singapore, Hong Kong or the Westin Tokyo because these are cities where I could easily be happy for a month. Another idea is Kuala Lumpur, which had a number of Starwoods and is generally an inexpensive city.

Do you want a resort-type property? Any visa restrictions? Something like LRM Shanghai (which has a good lounge) would be in the budget if you can find good rates for most nights.

Note that your status benefits last through February. IIRC it's normally the check in date that counts, which would mean that even if the stay stretches into March, you should still get Plat100 benefits at the hotel, although you might not get the third and fourth point at check out. [if points matter, would it make sense to split the month between two properties for this purpose, changing hotels a few days before the end of February?