Vehicle diagnostics - opinions

Up until now, we have outsourced our pre-mapping diagnostics to a third party, but we've decided we'd like to offer it as a service to our customers.
We don't need a tool that can reprogram extensively, just one that is decent at picking up fault codes and explaining them. The idea is that if we identify any issues, we can give the customer the choice whether to go ahead with the remap or to resolve the issue first.
I've heard mixed reports about Snap-On kit and Delphi are supposed to be good, but pricey.
So, what tools do people use on here?

I'm currently looking at something like this: Autel 808

It seems that genuine equipment is hard to distinguish from knock-off, which is a bit annoying!

I can ask Motormech which kit they use. They have tried Snap-On and found it to be lacking and they now use a different kit that they are very pleased with

Thanks Nigel, I'd appreciate it.

We don't need the last word in technological sophistication, just something that will give a reasonably reliable reading of fault codes so that we can give our customers the info.

Insert standard quip about Jim and technology

I would have inserted my own, but I don't know how...