20 Icons for Desktop Application

Require 20 icons to be created for a desktop application that we are writing.

None

Tagline:
None

Desired Color Scheme:
Any

Desired Style:
Must work and look ok on PC (XP and Vista) and Mac

Accepted File Formats:
Standard Web Formats (.jpg, .gif or .png); .ico and .png

The icons need to be created so they look ok on the PC (XP and Vista) and the Mac.

We require all icons in 3 different sizes (48 * 48), (32 * 32) and (16*16).

The application is a desktop application for a window cleaning business and the icons needed are the following:

1) Application Icon

2) Customers

3) Schedule

4) Calendar

5) Expenses

6) Alerts

7) Debts

8) Accounts

9) Reports

10) Tools

11) Settings

12) About

13) Exit

14) Marketting

15) Work Unit (This is an icon that represents a logical unit of work i.e a grouping of tasks)

16) List Maintenance (This is an icon the represents an ability for the user to add values to a list i.e expense types, payment methods etc)
17) Backup Utility

And the addition of possible 3 more as we develop the application.

Please ask me if you require anymore details of what the icons represent.