Rummy-nose or lemon. Rummies are gorgeous fish, but they're not as hardy as lemons and I believe the lemons will hang out a little higher in your tank which would be good considering you've got your bottom-dwellers picked out already.
It would require plenty of driftwoods to make a big difference in the pH. Also, the amount of peat used is based on trial and error. You'll need to determine your hardness levels to see how much easier to lower the pH.One thing I would watch out for is the ph, a pH of 8 is pretty basic, and fish that prefer a more acidic pH would probably not do great in that high of pH. that being said, I'd go with the rummies or lemons. If you get real driftwood, that may help release tannins, but not sure how much affect it would have. Also, make sure your LFS's tanks are at pH 8 otherwise your looking at some pH change stress. Good luck to ya!