I just purchased the SampleTekk White Grand [
http://www.sampletekk.com/proddetail.php?prod=STDELIVER-019-FORMAT ] and also their SampleTekk Black for Kontakt 5 [this one:
http://www.sampletekk.com/proddetail.php?prod=STDELIVER-039-KONT ]. Both are excellent for pop, country, rock and even Jazz. I am very pleased with this purchase. I beleive both are still 50% off through end of July--I think. Be aware that the SampleTekk Black requies Kontakt5 and comes with a liscence code for Kontakt 5 player; it is easily tweaked by the GUI designed for Kontakt 5. The White Grand works on Kontakt 2 thourhg 5, Halion and Gigastudio3. They are my goto pianos right now. I don't own IvoryII and have often wanted to get it, but now that I have these new SampleTekk versions, I am set for my pop,rock,country,Jazz mixes. BTW, I like the PMI Bosendorfer 290 and the Emperor and the Old Lady, but for your question I use the two I linked for you and they are running about $50 a piece while this sale is ongoing. Here is a thread downstair on the Gear/software forum where these have been discussed:
http://forum.cakewalk.com/tm.aspx?m=2601216