I am in the market for a La Pavoni, preferable the pre-millennium pro model. Looking for advice on a good grinder to pair with it, given that finances are very tight. I found for sale, a commercial La Pavoni grinder, about 6 years old, needing a new hopper, and ground coffee cover, for what I feel is a good price. Advice please?

Barry, there's lots of good advice here. A good espresso grinder is a good grinder for any espresso machine. For a question like this it's good to read the FAQs section of the Buying Advice forum on grinders. This kind of question has been answered well many times. From that section you might start here.

How to choose an espresso machine and grinder at the "right" price

The FAQs in the Grinders forum can be very informative too.

Dear BarryS,
It is not hard to help yourself by doing a little legwork. The search function on this web site is much more useful than the functions on other coffee sites and you may want to make use of it. For instance, on this web site you could come across inexpensive grinders specifically selected to fill the needs of folks just starting out with a LP. It is my post about a week ago. Scroll down to the bottom of page 1:
Newbie La Pavoni question - coffee flowing even before pushing the lever down
More expensive, but better grinders may be found using the product review depatments on this site and elsewhere.
Buckley

BarryS wrote:I found for sale, a commercial La Pavoni grinder, about 6 years old, needing a new hopper, and ground coffee cover, for what I feel is a good price. Advice please?

A photo would be helpful. Generally speaking, used 64mm commercial grinders usually sell for a couple hundred bucks if they're in good working condition, more if they're a marquee brand like Mazzer. You can usually replace the burrs and it's good to go. If any parts like the hopper are missing, the sales price takes a big hit because buyers don't want to be bothered with sourcing parts.