Need some advice about builders/kitchens/architects!

[missrose]

We're planning on redoing our kitchen and bathroom which will involve:

kitchen

removing an exterior wall (and extending into an outhouse)

removing a chimney breast

ripping out kitchen and replacing

new floor and all decoration

bathroom

ripping out bathroom

installing walk in shower

installing new bath

retiling and all decoration

We're not planning on staying in our current flat for longer than a couple of years (growing family) so don't want to spend a fortune but also want it to be done to a fairly high spec so it's easier to sell.

Would I need an architect for this, and a structural engineer to remove the exterior wall? I've no idea how much these things cost and would love some advice as well as recommendations for builders/architects/surveyors.

Thanks