Your gearbox rebuild specialist is the only one who can give you an informed cost of your particular box.
Every thing else is just speculation as each box is different, and that is why peeps, including myself are reluctant to price up for you.
Alex.
Agree, that is the way to go.
I have just fabricated a tool for removing the rear sub frame diff bushing in situ.
Not difficult to manufacture this sort of tool, all you require is a mate with a lathe and the correct dimensions.
Alex.
The Brembo fronts will be very tight, however they won't shear, just apply even pressure at the correct angle using a large breaker bar and an impact socket.
Here you go OEM from concept or loads on Ebay
https://conceptzperformance.com/Cart/description.php?II=9248
http://www.ebay.com/bhp/nissan-maxima-timing-chain