Welcome! You will find this board is full of nice people who will readily help you out.
The tape deck can be replaced easily with either a "Business CD" unit, or an MD player. For more info, check out all possible parts at:
www.realoem.com
27000 miles is very little! My CPO 2002 4.4i had 33000 miles when I bought her, and now she's pushing past 40000 miles!
Have many more happy miles ahead.
EDIT: I just noticed that while you don't have the CD, you have the Audiophile system (DSP). You're not doing bad then, at all!