Hotels aren't set up to accept and hold mail/packages for several months. You can certainly ask, but the likelihood that any hotel would agree to do this is slim to none. It's simply too big of a hassle to take on.

I concur with FlyingUndderTheRadar. Have someone you trust at home hold onto your items and send them when appropriate. Or, simply buy them while abroad.

If you absolutely must have your items, I'd try researching the Argentinian equivalent of the UPS Store. A local store that handles international shipping and local mailboxes will probably be able to accept packages and store them until you arrive.