Please explain what exactly do you mean by "confirmation and posting", because there are several things you can post: a confirmation, a packing slip, an invoice... Your current statement sounds like "a confirmation posting and some other unspecified type of posting".
In either case, the framework (FormLetter) is based on SysOperation framework and does support batch processing. You can
On a sales order, when you click Confirm sales order button (in the action pane under Sell > Generate), you'll get a dialog with the Batch button you can use for this purpose.
You can also use the Select button to change the criteria of what will be posted, Late selection to let the criteria evaluate when the batch runs (important for recurring batch jobs) and so on.
You can also call the posting framework from custom code, which is a different thing than ignoring the framework and trying to implement the batch support again on your own.
