Here are some options for DIY kits for your self install.

This kit will provide you with all the items we think you would need for supply outlet in each bedroom, sitting room, dining room. Two extraction points in the kitchen, one in each bathroom.  Included in this  are the manifolds, connection to the ventilation machine is not included until you decide type and position of machine. 

MVHR 3 bedroom 3 bathroom

This kit will provide you with all the items we think you would need for supply outlet in each bedroom, sitting room, dining room. Two extraction points in the kitchen, one in each bathroom and the utility room,  Included in this  are the manifolds, connection to the ventilation machine is not included until you decide type and position of machine.

MVHR 4 Bedroom 4 bathroom

This kit will provide you with all the items we think you would need for supply outlet in each bedroom, sitting room, dining room plus one other. Two extraction points in the kitchen, one in each bathroom and the utility room,  Included in this  are the manifolds, connection to the ventilation machine is not included until you decide type and position of machine.