System Upgrade - views/suggestions please

[rsr]

Hello

I'm looking for some ideas on how to upgrade the following set up and system.

Private water supply (pumped and filtered plus small accumulator)
LPG
Mains electricity

Boiler Ideal Mexico 28kw floor standing heat only on a Y plan. Open vented and pumped.
Aga oven with second HW circuit via open vented cylinder.

Property is 2 bed farmhouse with only 4 low water content rads (planning to replace with 6 doubles).

Obviously the boiler is oversized.

Any bright ideas welcome

Thanks
RSR