What should I do?

I need opinions. I'm looking to build the drivetrain in my duster. Right now I have a tired 318, a good 904 and 71/4 rear. I want to get a new engine. I have about $3000 to spend. I could rebuild the 318 or I have a 360 that I have had siting around that I could rebuild or I was toying with the idea of just buying an engine. I found this site anyone ever buy from it http://www.rebuiltcrateengines.com/dodge-318-challenger-p-2117.html
Any ideas what would be the best. I'm not looking to build a race car just something to run around on the weekends in.