As for RNGing, it wouldn't be a bad idea to pick up an extra game 2nd hand - $15-20 us about average, and probably worth it.
That said, I don't think RNGing corrupts your game, so you don't need a new game to do it. I personally don't know how to do it, but it's definately a skill worth picking up - it'll make online wifi battles a lot easier/cooler.
Edit: The alternative is to just get a perfect ditto or 3 and breed the old fashion way on HG/SS... of course it'll take A LOT to get something good.
Meanwhile if you RNG, you can get something good in like 2 hours.
I just read your post.
I'll do it for the Rosalia and for 2 credits in your thread in the future. These are fully redistributable, so hopefully you can put them in your thread and build a RNGed base of other people's RNGs like me. :P