You can use the form for payments/donations buy you have to have a wufoo paid account at the $29.95/month level. You can actually get the first 5 transactions without the paid account but after that you must pony up.
You can accept payments via: PayPal, Google Checkout and Authorize.net.
I don’t use the paid account but have been using wufoo with mailchimp for other sites not wordpress related. Because Wufoo has an RSS feed for your submitted forms, as long as aweber can capture the feed, it should work. Maybe try a google search for “wufoo and aweber.” I’ve just installed the wufoo widget here:
NB: I host a css file (easily done through something like dropbox) for the submit ‘ugly button’. ;) I’m also still playing with the size as it’s too big imho.