Congratulations on your upcoming wedding!
The relevant Velocity redemption tables are here. They tell you that if will cost you 127500 Velocity points to fly to London using Virgin Australia/Virgin Atlantic via Hong Kong, or 139000 points to get to anywhere in Europe using Etihad or Singapore Airlines. You need to look for “Reward” seats rather than “Any Seat” seats.
It’s too early to search for your flights on the Virgin Australia website as they have only opened up bookings up to the end of July at the moment. So if you want to use Velocity points you’ll need to wait another couple of weeks.
If you want to convert your Velocity points to KrisFlyer, I can see plenty of Saver availability to London on Aug 9, 2020. There’s also Saver availability to Paris on August 10. It’s too early to look for September flights.
My suggestion would be that you try to fly into London and return from Paris, rather than the other way around, as your fees and charges will be less that way.
The issue you have is that you have enough Velocity points to get to Europe and back in Business for the two of you … but if you convert your points to KrisFlyer you won’t quite have enough. So my advice would be to wait until Virgin opens up the bookings for the dates you want, and go from there.
Finally, be aware that Etihad availability is generally better on the Virgin website, compared with Singapore Airlines availability. The downside is that the carrier fees and taxes on Etihad are considerably higher.
I hope this helps!