Dear
You dont have to ask the embassy for extra forms, you can simply download B4 and B4 forms from the CIC and CBSA websites.
Remember B4A is just an extension of B4
You need
Take 2 copies of B4 for AG
Take 2 copies of B4 for GTF
One copy of each Immigration will keep
B4A u use if you run out of space on B4
Instead of B4A you can opt for Excel spreadsheets (as Qorax has explained elsewhere)
Thanks