There are many avenues to take for what you’re trying to accomplish.
http://codex.wordpress.org/Integrating_WordPress_with_Your_Website
Some people would just iframe jobstr.net to jobstr.com/blog, but we don’t recommend that as you lose basic SEO and user-friendliness.
Any decent web designer that you work with be able to get the integration done without “losing” any parts.
So, it’s not a matter of the possibilities, it’s a matter of finding the right pro. This can be a difficult task.
Post on http://craigslist.org/ and http://jobs.wordpress.net/ that you’re looking for a web designer/programmer with WordPress experience. Don’t pay for any premium job listings anywhere else, you won’t get any better results or different candidates. At this point, screen screen screen until you have narrowed down to someone you’re fairly confident with.