I process my herbs much the same way as you do, except I send them all through the Excalibur. I can control the temp and they stay real dry until I can vacuum seal them in jars.
If I tried to dry them as you do, they would mold here. We have real high humidity except in winter. I also use hay mulch under the herbs and this keeps all the dirt off them.
Fall and winter are low humidity here. have a similar machine with timer, fam, and temp control. For herbs its always low temp.
Vacuum seal sounds good. I just throw it in a jar and keep bulk in sealed baggies.