I had roughly about 130 albums and it did start to struggle a bit. Smooth scrolling had to be turned off and even then, whenever you hit the scroll buttons, it would hesitate a bit. This was with the database option turned on.
The delay you were experiencing would have simply been the album art loading in the background before it's displayed. The Static Databse simply saves the album/song lists to a couple of files so it doesn't have to search your paths every time it starts up.
I used to run SKJB on a P3 800, with a pretty decent video card. That was enough for it to run fine, although I had to tweak the animation settings a little before I got a smooth-ish result.
That PC then died on me (just the motherboard, thank god!!), so I got a cheap Celeron 2.4 (or something around that range). That runs SKJB perfectly!
I'm sure SKJB would run on the 533 you are looking at, DC, it's just a matter of how well it runs! To be honest, I would throw more at it, maybe get a 1-1.5 Ghz CPU and a decent-ish video card.