I dont know but they dealer said timing belt so

I guess it's not the chain.  It's a 2004 Sienna so it may not have the new chain.  Also, should I just buy the genuine Toyota part and have a cheaper mechanic do it?  I do know a Vietnamese mechanic who is good.  But do you think he knows the Toyota requirements as advertised by the dealer?  Don't want to spend too much on it but want it to be safe