Tony;
They are all good machines, I just think the smaller Rikon might be a better fit for your small shop. But again, make sure you can readily obtain filters for whatever unit you decide on. A remote is a must, as you don't want to climb on a chair to turn it on or off. A timer is essential, too. You want to be able to have it turn off after a set period at the end of the day. A light to indicate it is on is a good thing, too. Most of these are so quiet, you will not be able to hear them running! Don't forget placement. I recommend hanging it close to your DC. The dust coming from the cloth bag on the DC is where most of your problem will be. Make sure you have an outlet close by for it and it can handle the additional load. Most of these have a very small amp draw, but what else have you got on the circuit?
Last but not least you can build one cheaper and better than any commercial unit. Make it fit the size you want, use high quality filters you can get anywhere, and for cheaper. Let em know if you want the plans emailed to you!