Setup and communicate between multiple rails user profile/roles

Question

A marketplace allows users to buy and sell items. It construct of User model and Item model. Each has many attributes, and their association is:

user.rb has_many :items, dependent: :destroy, inverse_of: :user

item.rb belongs_to :user, optional: true, counter_cache: true, inverse_of: :items

Each user show view is alike a profile where it shows all selling items.

Now, I want to introduce 2 type of users. Single seller/buyer (sell and buy few items) and Business (sell bulk/buy small or bulk items).

I created 2 models.

Client

belongs_to :user
has_many :items, dependent: :destroy, inverse_of: :client

Business

belongs_to :user
has_many :items, dependent: :destroy, inverse_of: :business

NOTE: While Business and Client share few attributes, they have many different ones. That's why I created 2 models.

And User

has_one :client, dependent: :destroy
has_one :business, dependent: :destroy

Also Item

belongs_to :client, optional: true, counter_cache: true, inverse_of: :items
belongs_to :business, optional: true, counter_cache: true, inverse_of: :items

While I "feel" it is a good thing to have separate models, I "fell" it's complicated when it comes to item creations and each entity show view.

Required flow

When a user signin, it is redirect to /roles/new view and choose to create a Client, a Business or both roles/profiles.

After user have one or both roles, is able to create an item.

Before in item_controller.rb I would do

def new
  current_user.business.items.new
end

Now, I'm not sure. I want to differentiate between which role create an item!

  def new
    if current_user.client
      @item = current_user.client.items.new
    elsif current_user.business
      @item = current_user.business.items.new
    else
      current_user.items.new
    end
  end

Does it make sense???!!!

Is the user a Client, Business or both. This is needed to show client's items in its' show view, same goes to Business.

While most likely User with either Business or Client role would not create the other role but it could happen. A user have both Business and Client roles.

A user with one or more roles should create an item, this item belongs to the role/profile that created.

I think of it like, an application has Developer and Employer profiles. Both belongs to User model and both could create/has many Projects.

Am I making the process complicated for myself or it is solvable?