John,
Now days most of the computer will work. I have and it works fine:
- Dell Latitude laptop
- C5 core CPU
- 16GB RAM
- Intel HD 4600 graphics cards
Saying all that it all depend on how big your designs and how involved you are going to get with 3D. If you really want to push the envelope go for the best graphics card with most RAM on it. We had good performance with top nVIDIA graphics cards.
Regards, Yan