Originally Posted by lvfast1

I do Hvac by trade and a 5cfm or 7 cfm is adequate for residential/commercial systems 1.5-3 cfm more than enough for automotive a/c if you leave it on long enough with no leaks...micron guage would be nice but not necessary if no leaks and proper manifold setup and digital scale to weigh in correct charge <-(very important on cars)...definetely dont need evac/recharge system especially if it happens to not have "any" charge when you start no recovery needed...i look on ebay quickly found many that would work...Hvac supplier in your area should sell them also..wholesale if you have a contractors license...JB and Robinaire are good brands for everyday use but a cheapy fine for what the average DIY automobile owners need.
http://cgi.ebay.com/JB-Industries-DV-142N-Fast-Vac-HVAC-Vacuum-Pump-5cfm_W0QQitemZ310125939114QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item310125939114&_trksid=p3286.c0.m14&_trkparms=66%3A2%7C65%3A15%7C39%3A1%7C240%3A1318 <-great unit good brand

http://cgi.ebay.com/ebaymotors/Refrigerant-Vacuum-Pump-1-5CFM-for-Automotive-HVAC-R_W0QQcmdZViewItemQQ_trkparmsZ66Q3a2Q7c65Q3a15Q7c39Q3a1Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q2em14QQhash Zitem250379900114QQitemZ250379900114QQptZMotorsQ5fAutomotiveQ5fTools
^-will work for automotive but will have to run a while to acheive desired vacuum but economical.

Hope this helps

Arlo