Don't get a park bench like that orange one.. you'll look like a typical retarded fast and furious gawking teenager. Trust me, you won't impress anyone with that, people will just laugh at you.
On a side note.. I haven't seen anyone rock the Grand Am SC-T spoiler on an Alero.. I was going to, but I happened to get a different car before I ever bought the spoiler. I personally think it would look really good, you should give it a try.
Here's a link to a picture of what I'm talking about, the installed spoiler is the SC-T.