Aggregating a lot of Data based upon criteria

Hello!

I'm about to embark on a big task and I would appreciate any thoughts on how to go about it (the structure of it if you will)

The project: I have clients with many different accounts that all have different characteristics. For example, Joe and Jane Smith have 10 accounts. 5 of them are taxable, 5 are tax exempt. 2 belong to joe, 2 belong jane, 4 are joint, 1 is a trust, and 1 is a foundation. I have a page (Data) that lists all of the characteristics (row A is the account #, row B is the tax status, C is who they belong to, etc.). I also have a page (Account Detail) that breaks out the holdings of all the different accounts (domestic equities, int'l equities, bonds, etc.). On a seperate page (Account Summary), I would like a condensed version of the holdings report where in cell A1 I could say "tax status" and it would show me the consolidated holdings broked out by the tax status, or I could change A1 to "Owner" and it would break it out by Jane or Joe or Joint.

What I am thinking of doing (generally): I'm very fluent with index and matching, so if everything is labeled correctly, I could say ok, if A1 is Tax-Status, list all of the Tax-Status Categories, and then the column would look at the Tax-Status Category and sum the proper values of the accounts in the category. Then you change A1 to "Owner", it would list all the Owners (Jane, Joe, Joint, etc.) and fill in the values based on whether the accounts are Jane's, Joe's, or Joint.

Problems I see:
1) There are more owners (4) then tax statuses (2), so if I make 4 columns and change it to tax status, I get 2 empty columns. I would like the numbers of columns to automatically adjust by the number of categories so I have to do as little as possible manually.
2) I haven't thought it through, but I'm not sure if the index/match (combined with sumifs or something) will be able to say "ok, look at the data page, see which accounts are Janes, then find those accounts on a different page, and add the values together on this page".

Eventually, I hope to have a template file that I can just fill in for every client and everything will work well. The above (and attached) is a very simple example of the eventual project, but I'm hoping to get some take-aways that will allow me to expand this in all dimensions.

Please feel free to ask questions and prod me about specifics. This is as much a learning experience for me as the eventual product will be helpful for my job. I'm extremely grateful for any help related to any part of this. If anyone thinks there is a better way to go about this or other helpful functions (or macros, which might be the way to go, cause you could just run the macro when you change the input and the macro would do everything right based on the input....)

Thank you thank you!