C.C.
I'm wondering why you can't just get a large monitor and a docking station for your laptop? If you need more memory on the laptop, you could either have more memory added to it, or if it doesn't have room, you can always get an external hard drive. You could easily do that for your $350 budget. Just a thought.
In terms of reviews, we have always owned Macs, and I would recommend them without hesitation. Currently we have a 27" iMac and a 15" MacBook Pro. They are both well above your budget, but you could probably pick up a used iMac for a good price if you definitely want a new computer. Our last iMac was 9 years old when we purchased a new one, and the old one is still in use (it's the kids' computer now ;).