Multiple Hot water system(s)?

Want hotwater setup that allows the Main bathroom and Ensuite both have strong supply of hotwater when both are running at the same time.

Have family of 5. May have guest so needs to work with 6 people

What is a good setup.. we have: main bathroom + guess bathroom + laundry + suite + kitchen

I was thinking keeping the main bathroom & ensuite separateperate as they would be the most frequently used.

Two instants
1 Instant hotwater system to ensuite + kitchen
1 Instant hotwater system to main bathroom + guess bathroom + laundry


1 instant and 1 solar
1 Instant hotwater system to ensuite + kitchen
1 Instant hotwater system to main bathroom + guess bathroom + laundry

any other ideas?