Hi there, I was looking for a Laptop to start working with Inventor as well.
First I'd like to suggest for any software that you check out the system requirements, it's a good starting point those can be found here:
http://usa.autodesk.com/adsk/servlet...&siteID=123112
The next thing to figure out is your budget. If you don’t have your price range set before you go looking at computers then you may end up spending more then you want to.
I also would recommend Google searching for Autodesk Inventor to see what other professionals have used and what has worked for them. One of the things that I came up with in my searches was that Inventor works just as well with a gaming graphics card as it does with an engineering graphics card. With that in mind you can double your Engineering laptop as a sweet gaming system as well.
As for “Refurbished” or “Recertificated” hardware I usually like to stay away from it. However that does not come from any issues I have ever had before it’s just a personal preference. The important thing to do if you wish to purchase used or ever new for that matter is check the return policy.
Keeping all of that in mind a good place to search is new egg, you can do a power search and enter in what hardware you are looking for and they have usually have a good return policy plus really good customer service.
You can also try tiger direct, Fry's Home Electronics, Micro Center, and any place else you like to shop.
Hope that helps.