The thing that truly revolts me about this question (++) is that you could probably write the damn thing in C (how's that for speed) almost as fast as you could write it in Jyva. The benefits of using Jyva probably wouldn't come in to play much with a project like this, especially if you are on this project by yourself. The whole world seems to think that you have to kill knats with a sledge hammer that's painful to lift.
I vote for the "write a test version in perl". It seems like you could write something in no time flat. If you want perl to work for you, you have to work for perl. Work late one day if you can't get it done during your regular work schedule. Then tell them how long it took. If you're worried about there being repercussions, just say it was a working model for the java version ;) Remember, it's better to ask for forgiveness than to ask for permission.
Or if you think you're going down the toilet anyway, just write it in perl, hand it to them and say nothing. See how long it takes them to notice the difference ;) (just kidding)
(thankfully I no longer program in C for most things)
PS I have never worried about there being other perl programmers around to maintain my work. Currently I'm the only perl programmer where I work. Like most work places, mine likes to make me feel like I'm easily replaceable. So I act like I am ;) Oddly enough, most of my programs have never had problems, and usually they are retired before they ever do (the oldest running program I have is 3 years old). All because I have the time to test my programs because I'm working in perl.