I recommend the Dell XPS desktop. Can't recommend a laptop if you want to run a business. I'd go top of the line up to, but not including, the "gaming" model if you can afford it. This is a very fast responsive computer. However, this model might cost you over $2000.
You can still buy the XPS at a lower price, though by choosing less memory, smaller hard drive and mid-grade graphics card. You wouldn't need fancy speakers.
You can customize, so I would include as much memory as you can afford. Don't skimp on memory. Same with the hard drive. Some come with two drives, one called an SSD drive. I recommend. Also the latest Intel chip; which I think is still the i7. You will also want a large high definition monitor...at least 24 inches, but I'd go 27 inches, again if you can afford it. The Ultra Sharp is very clear.
I can't recommend another Dell model because, in my experience, the XPS is an exceptional performer. Using Dell's for about 25 years. No hardware problems ever.
If you can hold out, Dell has some very good sales throughout the year.
Dell's tech support has been somewhat problematic in the past since it moved to India. Very difficult to understand techs and often we are given those who are just learning, but they have experienced techs who help them if they run into snags. You just need to be careful they don't do anything stupid. By that I mean, I had one that did. Nearly had a heart attack.
I think all manufacturers are using foreign support now, so users are at their mercy.
You would be better off to take your computer to Best Buy or a local techie to fix if you have a problem. More than likely it would be software or a "bug", not hardware.