That's a great setup you have there, alot like mine in fact
I moved one of the drive cages to keep the extra 3 drive bays.
http://picasaweb.google.com/bbopptech/LLV1000Pics
Cooling performance 'could' be effected by the pushing fans but the front fan and rad combo can be removed using the 2 spring-loaded Lian Li screws for easy filter cleaning and the rear I usually just wipe off the back grill every month or so (and both my fans are 38mm intaking air from the outside, both front and rear) but the difference isn't major enough to warrant changing my setup and pulling hot air from the mosfets through the rear radiator isn't something I want to do when this case is so 'open' to the environment. Because of this all my fans push cool air into the case and heat rises and comes out the top front and rear of the case nice and steady, and it's usually fairly cool air as well. I just 'sat' one of the ADDA 120's that came with the case between the front 5 1/4 perf grills and the relocated drive cage. It fits snug and doesn't move or rattle and provides additional air to the drives, additional air to the mosfets, and looks good too
I love the setup, all in the case, good temps, and nice and quiet... you'll love it when it's done.
This is my first venture into water cooling and I did a great deal of research first however I made compromises in the rad set since my primary concern was 'quiet cooling'. I'm sure many of the members here know a great deal more than I, however I'd be glad to answer any questions you may have because I've had experience with this similar setup.