Looking for Multihoming / Loadbalancing products

Dear all,

Can anyone suggest me some decent product which have the ability stated in the subject?

Currently I am using Ascentlink 320 which I bought it near RM10k in my country (Malaysia). Now I need a multihoming router or loadbalancing enabled product for my temporary site office.
Since it is for a temporary site office which will continue to operate till the year 2009, so I wish not to spend so much money on it.

My budget for this coming gadjet not more than USD800, so anyone got good suggestion?

Thanks in advance