Um, I think that's exactly the OPPOSITE of what everybody's saying. But hey, if you can't listen to what people here are saying, when it's spelled out for you, you probably won't be able to listen to what people are saying during a 121 training course. But hey, what do we know.

You have your CFI. Go out for three months and work on it. If you don't understand the terms of flying a jet, no biggie, get a book on Aircraft Systems, and do it that way. Spend the three months actually getting flying experience and learning the terms inside and out rather than just the overview provided in an RJ course. Trust me, you'll do much better in the 121 training and you'll be much more marketable to airlines, especially when they ask you "Why should we risk $50k on you to train you to our specs?" The fact that part of your answer will (should) include that you preprepared by reading through systems books so that you knew how all the systems worked fundamentally will show that your initiative has no bounds. And that's much, much more valuable than any RJ course.