I think a good computer for your needs would be the 13" mid-2012 MacBook Pro. This was the last of the Unibody MacBook Pros and was in production until 2016. As such it has more time until the typical 5(ish) years after which Apple considers placing it in the "vintage" category where Apple won't provide service parts (unless you're in California or Turkey). The other advantage is that it has a SATA III interface to take most advantage of SATA SSD speeds. I believe the 2010 MacBook (the polycarbonate one) is only SATA II. It's also only a Core 2 Duo processor, which is somewhat outdated, while the Core i5 in the mid-2012 MBP is still a decent performer.
The other thing is that since it was on the market for over 4 years, there are a lot of used ones out there used and in good condition. They're desirable because they have a lot of different ports including ethernet, FireWire 800, and an SD slot.