Thanks for your interest with our products and congratulations on your business upgrade, @DaveC23,
All QBO versions such as, Simple Start, Essentials, and Plus are designed for different business types. These services can track a partner's disbursements and profit allocation. All you need to do is create a supplier profile for each partner and a separate equity account for them.
The steps to do that is listed in this Community guide: Add an owner or partner to your books
Regarding your second question, there are several reports in QuickBooks where you can track a partner's threshold for estimated tax payments and self-employment taxes. To get an immersive experience before purchasing, you can sign up for a free trial with us. This way you have an overview on which program you want to get.
Check out this link for our QBO feature comparison and free trials: QuickBooks Online United Kingdom Plans and Pricing
I'm also adding a few related articles to help you configure QuickBooks for a Partnership business:
Feel free to ask me if you have other questions about this topic or need other help with setting up your account. I'll be right here to help you. Have a wonderful day!
