If your 1099B shows that basis WAS reported to the IRS for your transactions (i.e Box A or Box D), then you can just mail the summary page showing the total information. In these cases, the IRS already has your 1099B information, so you are just following up with the summary totals and there is no need to resend them the same information.
It is only if your basis was NOT reported to the IRS that you would need to send the entire packet. If you are unsure, then you should err on the side of caution and side the whole packet, but it seems that you have indicated these are all Box A transactions, so you are fine with the summary page.
