The aluminum ones won't fit on a D90 ST without modifications. You need a POE top which are rare.
I have a fiberglass one for sale in Washington DC if you're interested:
And there is a guy closer to you with an incredible price:
The fiberglass original hardtops are delicate when off the truck, but once you get them on they are actually quite sturdy. They are delicate because if you drop them on an edge the old fiberglass doesn't flex like it did when new and they can crack or chip. Twisting the top when its off the truck can also cause stress cracks. Once all bolted down on your 90 they are solid.