Finally upgrading to digital, could use some advise

[Singletracklovr]

So do you think that I should stick with both Quantaray lenses and spend some money on a 50mm lens to start on portraits?

If I were you I would buy the d90 and try your lenses.
Since there's no developing you will instantly see your results. Post some up here for friendly feedback and check others user galleries to compare your pict quality. You might find the lenses you have are fine. If so you have more budget to expand your lens choices. If your not happy you can find the VR lenses at very good prices. B&H is a great place to shop.

The nikon 105mm f2.8 might be a good portrait lens to lookin to and you get the macro feature to boot.
Outdoor Macro shots really spices up your photo album IMO.

This thread from Didache has some of the best advice I have ever found when I was researching camera gear.

15 Truths about Photography