Combi boilers connected as zone valves

[manta]

Hi everyone!

I'm trying to upgrade my existing system(s) with evohome.
The two story house I live in has two separate heating system in it: each with it's own CH (Vaillant AtmoTec plus VUW 200 and a BOSCH Gaz 3000 W) providing heat to 8 radiators downstairs and 6 radiators upstairs (3 and 5 zones respectively), each radiator fitted with HR91's.

I tried to reach out to one of my local Honeywell reseller asking if I will be able to connect both systems to one controller. They said I have two options:
1. To use two separate controllers, each controlling one CH.
2. Use one controller, add the two CH as zone valves, but then I need 3 BDR91's: one for downstairs, one two in parallel next to the CH with 5 zones, because of some maximum 4 zone limitation for each zone valve.

I did not have the courage to go with solution 2, as it seemed a bit "hacky", and choose to install 2 separate controllers in the house.
I'm still not sure if I made the right choice, this is why I'd like to ask what are your thoughts on the subject? what would've been right choice?

[Richard]

2 boilers = 2 evohome Controllers... Simple choice for me!