Electric Central Heating Boiler inquiry from Jordan

I really want to buy an Electric Hot Water Boiler for only Central Heating:

HOUSE SPECIFICATIONS:
(380 Sq meter)
( 1140 cubic m)
• Width: 19 m
• Length: 20 m
• Height: 3 m

The specifications of the
Boiler:
1. Material: Stainless Steel
2. Thickness: 10 mm
3. Volume: 350-400 Liter of
Water.
4. Insulation: 6 mm
5. Heat Exchangers: 4 Screw
Heaters ( stainless Steel)
or the best Heat Elements
You advise.