if you have lots of money, by all means get the aluminum wheel. There are several reason the lighter weight of the wheel is a good thing. The downside is that they can crack and get gouged up easier. No problem is you've got lots of money though.
If money is tight, get some steel wheels for $25 each. Then put the other money towards some good mods which would come in handy on Rubicon.... like rockers, lockers, roll cage, cool suspension tweaks, etc, etc.
In our area you can get white spoke steel wheels from Discount Tire for $25 each. Comes with a 3.5" backspace which matches Suzuki factory spec.
We prefer going with a 2.5" backspace, but those are custom wheels which doubles the price.
The best place for new "shoes" on a budget is used tire places. Lots of times you can pick up a set of used tires with wheels attached for next to nothing. I picked up a pretty new BFG 31" for $25 one time to use as a spare. Lots of times, these used tire guys will have matched tire/wheel sets from guys who upgraded to a larger tire. Price is always cheap too.