If I get a good humidifier do I still need to mist?
Yes, absolutely. A humidifier does not replace the requirement for a good watering method for your chams. Humidifiers raise the humidity levels, but do not produce enough drinking water for the cham, nor enough to allow the cham to clean itself.
In fact, for most chams a humidifier isn't even required. The humidity created by misting/dripping, and retained by having live plants in the cage, is usually sufficient to raise the humidity levels within the enclosure to acceptable levels. It is always a good idea to have decent digital hygrometer in the cage to monitor the humidity levels. In cases where the humidity is too low (like you live in a desert) or where the humidity requirement for the particular species you are keeping is quite high (like some montane species) you may have to resort to using a humidifier to maintain the right humidity, but that would be in ADDITION to other watering techniques like misting and/or dripping.
In most cases where humidity levels are too low it can be easily fixed before resorting to a humidifier by modifying the cage: denser planting of live plants, or solid back and sides rather than an all-round screen cage.
I found some personal small humidifiers but I dont understand how I would get the humidity in the cage without putting the whole unit in there and that doesnt sound safe.
You're right - it isn't safe to have the humidifier in the cage, nor is it hygienic or good for the longevity of the machine. If you need to use a humidifier, the following article describes the best way to implement it in your enclosures:
Humidifiers and Chameleon Enclosures
If you hand spray is that sufficient? What's the best(but not the most expensive) option?
Hand spraying is fine, and it is what most keepers use. But in most cases, one drinking opportunity per day is not enough for a cham, so you need to have the time to be able to provide more than one misting session per day, or supplement it with long sessions from a dripper. A misting session (whether by hand or not) should last for quite a while too - usually at least 10-20 minutes - since initially the chams will generally shy away from the spray of water, and it takes a few minutes of misting to initiate the drinking response from the cham. The amount of time involved in hand misting (especially if you are keeping more than one cham) is usually what prompts keepers to try and automate their watering systems.