Sadle-pack Lipo

[Lowie]

Hello dudes,
A simple question: Does anyonde know about sadle-pack Lipo's ... that are made with a hard casing!
Our Belgian RC-association seems to have decided that Lipo's will be in 2008 allowed as long are the have a hard casing. I know that Sadle-pack Lipo's exist, but have never found any with a hard casing.
I would like such a Lipo for in my X10 Pred.
I allready am the proud owner of two trakPower Lipo's which are simply GREAT, so EASY to use.

Maybe another idea, that just popped up ... maybe it is possible to buy a soft-casing-sadle-lipo and make some hard plastic casings for it?
Is this a crazy idea.
Any thoughts on what I should keep in mind when making this?

thx!