I need a new bannister/hand rail for my hall way (we took the old one down when re-dcorating & havent finished it

) so I need to know where I can get one - nothing special , how much they cost and who can fit one - the sooner the better really as my other half is nearly 9months pregnant and struggling up and down the stairs - would also like one for when baby has arrived to make going down the stairs safer...
so who can help ?
many thanks