The Kick 2 can handle 6amps and .5ohms coil. Of course, it will only put around 2.7 volts through such a coil so I wouldn't even bother with one that low. You can still find the original Kick for sale - but I would definitely go with the Kick 2. Where I bought mine from, the Kick 2 was only $5 more than the original Kick.
Just for the OP's understanding . .if you were to remove the kick and run your .5ohm coil, you would be vaping at around 30 watts. To vape at high power like that, you need a decent battery and, in particular, the airflow has to be right for your set-up - otherwise you get a nasty, hot vape with lots of popping and crackling from boiling e-liquid. You'll also want to tailor your juice to such a setup because some liquids taste better at high power than others. I find fruit flavors are horrible at high wattage but flavors like RY4 are nice. And don't forget the nic level . .if you're vaping at 30watts with huge airholes, you're going to want to lower your nic level a lot.
I truly find that with microcoils around 2ohm or so and cotton wicks, I'm getting the best vape experience of my vaping life. The clouds are a bit smaller (not much) but the flavor is a lot better and a whole lot more consistent. I did have some fun and good vapes with sub-ohm, though, but it just got to be too much of a hassle. For me, anyway, lung-hits at 30watts was not an all-day vape kind of thing and it just became annoying to maintain 2 sets of gear and juice.
So, if I were you, I would go ahead and get a kick - and if you want to play with sub-ohm - go ahead and get a dedicated rba for that purpose and, obviously, take the kick out when you use it.