How to Get "top N" and "Other Than Top N" values in SQL and SSRS?

Hi,

I have some data that includes Broker names, product they bought, and corresponding values and quantity of the products. I need to show top 4 brokers (each product wise) based on values of the product as well as "other than top 4". If for a particular product, there is only two brokers that have some value and rest of the brokers have just quantities and value equal to 0, then i want their sum to be removed from "top 4" field and added into the "other than top 4" column. I know it sounds really complicated. I am preparing this report on sql and SSRS. Below is the sample of desired report:

Sample Data Table:

product      Brokername      Values      quantity
Casualty        ABC                      500                2
Casualty              XYZ                      300                3
Casualty              LMN              250                4
Casualty              PQR               0                4
Casualty        OPQ               0                6
marine              XYZ                       200        1
marine              ABC                       300        2
energy              LMN               600        4
energy              MNQ               0                1

Desired report (On SSRS):


I have inserted the image of the desired report. I am almost done with rest of the data on SSRS. These are some of my queries.

Thanks