Here's a high overview of how to complete this along with the names of the files required to do this. Most of these files are available from the microsoft site. Just do a google search for the file name and you will be redirected to the download pages. Some files will require licensing (eg. Windows 2003 Server, MOSS and Visual Studio)
1. Install Windows server 2003 64 bit with ISO (SW_CD_Windows_Svr_Std_2003_R2_64-BIT_English_-2_x64_R2_CD1_ISO_MLF_X12-58050.ISO)
2. Install Windows Server 2003 SP2 (WindowsServer2003.WindowsXP-KB914961-SP2-x64-ENU.exe)
3. Install Windows Installer 64bit (WindowsServer2003-KB942288-v4-x64.exe)
4. Install .net Framework 2.0 SP2 64 bit (NetFx20SP2_x64.exe)
5. Install SQL Server Express 64 bit (SQLEXPR_x64_ENU.exe)
6. Install .net 3.5 (dotNetFx35setup.exe)
7. Install SharePoint 64 bit (OfficeServerwithSP1.exe)
8. Install Visual Studio 2008 from CD
9. Upgrade Visual Studio to SP1 (VS90sp1-KB945140-ENU.exe)
10. Install Visual Studio Extensions (VSeWSSv13_AMD64_Build-433.exe)
11. Install PowerShell 64 bit (WindowsServer2003.WindowsXP-KB926139-v2-x64-ENU.exe)
12. Install SQL Server Management Studio Express 64-bit (SQLManagementStudio_x64_ENU.exe)
Optional: Install IE8 (IE8-WindowsServer2003-x64-ENU.exe)