My htc evo 4G lte is aluminum, along with many htc phones.
Your coming to an android forum so most everyone will tell you go with android but it's really up to you of course.
The camera on my evo lte is awesome. Same goes for many android phones.I can get better close up shots than my friends 4s hands down. The iphone 5's camera hasn't changed really from the 4s.
As far as screens go if you want a larger screen android is the way to go. If you don't like the amoled screens you can choose a different style. That's why android is great. I love the 720p display on my evo lte. No 720p on the iphone.
For me it's a no brainer. I would pick android all day over ios. Iphone doesn't bring anything to the table that I don't already have in my 5 month old evo lte. I honestly have more features in my "old" phone. I say old because in all fairness it is running an "old" os in ice cream sandwich. And like I've told others, if you do choose to get an iphone don't get the 5. The 4s is super cheap right now and with ios6 it basically becomes an iphone 5.