I also had trouble trying to order from New Era recently - no response to emails.
My aluminum spindles are the RDLogics - bought them on eBay (and recently picked up another set):
http://compare.ebay.com/like/3102286...=263602_309572
I'm not sure if they're available elsewhere, though - nothing else showed up on google.
They have been fine so far, and what I like about them is the beefy arm (which is the weak point on the plastic ones) - but I haven't really put them through a lot, since I installed them near the end of the summer and really didn't run my buggy in the fall.
The only other ones that I know of are the dynamite spindles, but haven't found them available anywhere.
So I agree that it seems to be difficult to find any aluminum spindles - which to me are an important upgrade.
-brian
Edit:
Link to dynamite spindles on eBay:
http://cgi.ebay.com/DYNAMITE-DYN7224...item3f04707e92