Can I add hot water zone to this setup?

I'm looking to add a hot water zone on my gas central heating and trying to figure out if it's a big job or small enough.

House is 18 years old and originally we had zones for upstairs and downstairs on the heating (controlled by a light-switch style switch), but never had a hot water zone that we could turn on without the heating. The motorised valves were bypassed several years back when we had an issue with the heating, and it currently operates as all one zone - turning heating on turns on both up and downstairs.

Spoke briefly to a plumber who hasn't seen the setup, but says he has seen other houses in the area and thinks it should be a small enough job. Says he's too busy for now to take on the job himself, but has given me numbers to get quotes. Before I do that, just wondering if anyone can tell me from looking at what's in the hot press whether this is something that can be done easily enough, or if it's a big job? There are three boxes in the hot press that are just sitting, not attached to the piping. Two are the same as pictured and the other one looks similar but has no print on it. Would appreciate any advice thanks.