well done you for giving it a go! Your people skills will be your main asset, people buy people! It is hard work but enjoyable you will need to market,sell,market, non stop, be prepared to start off slow and keep the faith. Its tempting to be cheap to get the work, but you can end up being a busy fool imo.
The suppliers of kit you mentioned are all good ,buy from whom you feel most comfortable with, and hopefully they are close to your home.All the best. Remember to keep some money saved for the taxman, he will want his share . Simon