Jack,
You're on the right track. I feel your pain with the mdf dust. I've got your solution right there in your back pocket too. Go to Harbor Freight and pickup a 2 hp dust collector. YOU WON'T BE DISAPPOINTED!!!!! It's a must have tool. Get the $45 hose kit too. I'm not kidding, you will love the result. Hook it up to all your tools.
dust collector:
http://www.harborfreight.com/cpi/cta...emnumber=45378
hose kit:
http://www.harborfreight.com/cpi/cta...emnumber=93601
Your z axis looks good. Keep up the good work. The JGRO is a great cnc router. I love mine.
Dave