I'd buy a laptop that meets or exceeds the requirements if it was a job that was a good return on investment. Some laptops can take upgrades, but its best to have a laptop that was designed to run the faster CPU to avoid issues with heat disipation etc. Laptops are cheap these days and you should be able to find a used dual core meeting 1.8Ghz and 2GB RAM for around $200 or less. I'd go with a new laptop myself if it was for mission critical work, nothing would be worse than thinking your all set to go and having a computer get you fired when it cant work properly.