I think part of the reason your question about box mods hasn't been answered yet is that it's not super specific. A box mod is really any mod that comes in a box shape - it can be a mechanical mod like your penny or it can be a vw/vv regulated mod.
A mech box mod usually has two batteries running in series so that instead of using 4.2 volts when fully charged, you're using 8.4. The idea here is to get a more powerful vape. However, just like any other mech mod, the only way to adjust it is to build a new coil at a difference resistance, there usually aren't any safety protections except your knowledge level, and the vape will gradually get less powerful as the batteries run down. If you're running a 1.3 ohm coil on your penny, this is probably not going to be your favorite vape. These are for the guys who run builds down around .2 or .3 and still want more power.
A vw/vv box mod can have one or two batteries in series or parallel, and are fully adjustable vw devices with higher power ranges than the norm. They can top out at anywhere from 30 to 150 watts, depending on the model, and are adjustable so that you can use any power level below that maximum. Like any other regulated device, the power level stays where you set it for the full range of the battery, and there are built in safety features. Some people set them at one level and leave it there, others use different levels for different atomizers or juices, and still others want a more or less powerful vape depending on their mood, the time of day, or whatever other factor you can think of.
Right now, your 1.3 ohm coil on the Penny gets you about 13.5 watts of power when your battery is fully charged. I'd recommend trying out a vw mod that can do 30 or 50 watts. That will give you plenty of room to experiment with (and to grow on, as a lot of vapers' taste in power goes up over time), and if it turns out that your 13.5 is where you like everything, you can set it there, too. The big advantage to that is that every coil will get you the same vape, and it will vape the same on a fresh battery as it does on one that's almost dead. And with a way to adjust the power, you have a lot more control - you can really tailor your vape to your own individual tastes and preferences a lot more easily. Want to try something different? Push a couple of buttons and you're there, instead of having to wrap and install a new coil.
Hope that helps.
. With VW, as FrenchFry said, once you know the wattage that produces the flavor (or clouds) you like for any given juice, you can set it and forget it. You don't have to factor in coil resistance; the VW device will adjust voltage, taking into consideration the ohms, to achieve the desired wattage. Definitely makes life easier! But, if you most always use a coil with the same ohms, VV works beautifully... no need to constantly adjust it, either. If you can, you may want to get a VV/VW device.
