With a new system, you will need to reinstall all your programs. There is no way around it because programs are not only "program files" but a lot more such as registry settings, etc.
But your data folders, if they are in a seperate partion, you can just "include" into the Windows 7 libraries. That is the easiest course of action.
32GB for an OS is tight but will work if you take some precautions (control the shadowstorage, eliminate the hibernation file, etc.). My Windows 7 32bit is 15.4GB right now and I have quite a few programs installed. My 64bit Windows 7 is about 5GBs bigger.