I like the idea of your Centauri A sir Matz - since the lcd/plasma is mounted, nagagamit yung 3 levels for center speaker & gears.
However - if your longest rack the Sabre Titan has an integrated lcd/plasma mount - mas panalo!
Normally kasi with our typical 3 level av rack - the top part is for the lcd/plasma/tv, middle layer is for the center speaker, tapos all gears nasa bottom area lang - which most probably hindi kasya for future proofing.
A longer 3 component per level av rack with a lcd/plasma floor mount maybe a good ticket - wherein you place your center speaker on the top level & you still have 2 levels for gear placement. 6 gears could be placed. A total of 8 gears if you plan to utilize the spaces on both sides of your center speaker
That is also if your place can accommodate the rack
But i do like the modular concept of your crescendus - flexible & just buy as you need