Its not 'one of those forums', but asking where to buy a steering wheel from isnt the best place to start. Lets say you want a Nardi, your best bet is to search for places selling Nardis in the UK and pick one with an appropriate price (if its cheap its fake).
Regarding mapping, your best bet is to share your location and people can help you with who a good mapper is in the area. Then is to ask the mapper what a good ECU is/what they prefer (Power FC, Link, HKS etc etc) and then you try and find one of those.
Buying a 2 way new can be expensive and not many places stock new items. You can go on the SXOC/Driftworks for sale section and wait for one to come up or put a wanted advert up.
As i said, its not 'one of those forums' but just dont ask super vague/obvious questions. If you had asked who is the best mapper in xxx area then a bunch of people will come to your aid, if you ask where to buy a steering wheel from (surely you know this from building hondas) then you get a more abrupt answer. Ive now provided you with both lol