Q: What after-market repalcement batteries are high quality?

Apple's recommendation is you use an Apple battery from an authorized Apple Service Center.

I have used the Anker batteries with success, after 1.5 years they are still above the charge level of a new Apple battery, I use them because Apple no longer supply their own for 2009 MBP's, thus forcing the use of a 3rd party alternative.

Anker batteries are not the cheapest but are available from Amazon, or Anker direct.

You're welcome

Another option to consider are NuPower batteries from OWC.  I have installed one in my 2010 MBP about 1 year ago and the current full charge capacity is over the designed change capacity.  It is not the least expensive battery on the market, but less than the Apple price.

Avoid ebay bargains. In the long run they may cost you more.

Ciao.