Sim planning tool?

I have been considering investing in a sim that would be mixed residential/commercial, and as such have been tinkering with possibilities for different prim alottments per parcel. Up until now, for layout purposes, i've been using a basic grid in Adobe Illustrator and moving around appropriately sized parcels.... BUT - is there any tool out there that does similar work AND calculates possible alternative prim alottments and credits/debits a bank of prims accordingly? (IE: 0.5x, 1x, 1.25x etc)

Actually, you can do that quite nicely in Excel or another spreadsheet program by ...

1) Drawing a 64x64 grid (representing the region in 4x4 squares, e.g. from A1 to BL64)
2) Marking the parcels by letters ("A", "B", ...) inside the grid
3) Use coloured background to show the parcel outlines
4) Use the COUNTIF() function to automatically track parcel size [e.g. =COUNTIF(A1:BL64, "A"]
5) Calculate the corresponding prim allotment by parcel size [=15000/65535*COUNTIF(A1:BL64, "A"]
6) Play around with prim allocation by applying multiplicators to the per-parcel prim allotment, always making sure that your total is staying below 15000

YMMV, but back when I was a landlord I did it this way and found Excel quite satisfactory for this purpose.

Oooh ok, thanks Ricky!