I've done some hobbying in Kiev.  The trick there is to use Google translate to look at the local pages.  You will find good providers for much lower rates than the agencies.  It's been a few years since I've been there so my leads are cold, but that's how I generated them.  There are escort malls, mostly in Russian not in Ukrainian.  I've had a lot of fun there for a very low price.

One other thing: post your request on the FKK forum--that's where a lot of international travelers abound.

All of the local agencies I came up with in Kiev looked a little bit questionable, so I ended up going to the buddha bar and found a nice girl who started out asking for $300 but wasn't sure how long that should be for. So finally we agreed on 4 hours.  But Kiev wasn't really what I expected so I skipped Romania and went to Prague instead for more of a Western vibe. I ended up using www.babesandangels.com and was very happy.