[GawainBS]

I guess they didn't give you the items earlier because they are so powerful. It's not that PS:T's combat is the most difficult ever created.
There's a patch (I believe one of Qwinn's) that makes the Greater Glabrezu's available when your first enter Undersigil. IIRC, they also drop those items.
Personally, I find PS:T the better game, since it's deeper, has more character development and offers true choice. It also is less "bland"/"classis" fantasy than BG2. (Note: In no way am I saying that BG2 is a bad game.)