We have tried lots of different drying equipment. Some of our friends swear by a classic Food Dehydrator, 250W Large 5 Traysthe one linked to here has five trays so would be ideal for the amount of leaves and herbs you will be drying regularly.
You want one that is big enough with at least five tiers, but also with a timer. Some of our leaves are very quickly dried in a dehydrator so you need to keep an eye on them as well.
So perfect for leaves but if you want to dry out stalks of rosemary or mint then an airer, kitchen hanging air dryerill be a better option. It can be raised to the ceiling and kept out of the way in your kitchen or utility room. It allows you to keep a close eye on the herbs to make sure they are drying and not developing mould.
We also find that it keeps a lovely aroma in the home. Not to mention that it is nice to see what you are drying as a bit of a visual reminder to get the next stages and storage ready!