OK ... we're still at the dynamic flow part of the equation as the dynamic pressure is ok but the flow isn't the best, you will get an ok shower but you're really looking to get another 10l/Min dynamic for minimum impact when more than one HW outlet is open at the same time.
The Joule Unvented cylinders are OK, I like OSO Delta's as they have a great recover time.
Your boiler input can be lower now if you are using a system/HO system rather than a combi, or you could still use the combi and use it's HW outlet dedicated to one outlet. Lots of configurations are possible. You really need to sit down and work out exactly how you want your system to perform and then discuss that with a professional that understands and can design an advanced hot water system around the capacity you have, they should then be able to tailor your system to your requirements.
The Joule Unvented cylinders are OK, I like OSO Delta's as they have a great recover time.
Your boiler input can be lower now if you are using a system/HO system rather than a combi, or you could still use the combi and use it's HW outlet dedicated to one outlet. Lots of configurations are possible. You really need to sit down and work out exactly how you want your system to perform and then discuss that with a professional that understands and can design an advanced hot water system around the capacity you have, they should then be able to tailor your system to your requirements.