I installed the 64 bit PostgreSQL 9.0 on Windows Server 2008 and it seems to perform wonderfully.
I moved 1.5 million records that are 3K wide from SQL*Server into PostgreSQL and rebuilt 6 indexes all in less than 6 minutes.
I was thinking of using SQLite for the project, but I calculate the same data movement would have taken about one month!
The memory footprint is also very nice for the amount of performance delivered.