Hey there, @benjmurts,
I am afraid that this implementation may be possible with custom development, as that’s the Jetpack CRM Invoice Itemiser layout with options you can access right now:
https://cloudup.com/chOMB8vpc-9
However, we aren’t able to help with custom code requests like this, so if you need assistance, you may want to look into one of these services:
https://codeable.io/?ref=l1TwZ
https://jobs.wordpress.net/
If this option interests you, we do have an API for developers to access most data (and we’re continuing to expand that):
https://automattic.github.io/jetpack-crm-api-docs/
Note that we don’t currently have the bandwidth to do any custom dev work ourselves, as we’re focused fully on improving our core products, but several users have had success hiring freelancers as needed, so if customizations are very important to you and you’re unable to implement it yourself, you might want to consider going that route.
I know that’s not the sweet reply you were hoping for, but I hope it helps!