Jet version ?

Yes there could be a jet version.

http://www.jetcatusa.com/p200.html

2 x 50 lbs is possibly enough ?

With Jetcat 200 this would be able to fly 45-60 minutes and 30 minutes a full power.

The hull houses a lot of fuel...if needed.

here 4 x Jetcat200 http://www.youtube.com/watch?v=7Frc3-_64ns&feature=related

Here is a swedish AF new stealth design model with JetCAT engine; http://www.youtube.com/watch?v=B-_BvFadE7w