As someone who has neither..I'm probably the last person who should be giving advice. However, the pre-V pieces are really what the 'modern' Panerai is about. The 1, 4, 9 etc are all derivitives of those Pre-V pieces. You can talk all you want about how pre-A cases are actually pre-V just with newer dials, but it's still not a true pre-V.
Obviously, cost is an issue when you're comparing pre-V and pre-A, but if you can afford it, and your purpose is to 'complete' your collection, you MUST have a pre-V, as far as I'm concerned.
Now...having said that...can i buy your pre-A's.....??? hahahahahaaaaaa