Y'all showin that you never even dug into FL right now with all this "stock can't cut it" talk.
Between the downloadable content for DirectWave, FL Keys(with a few FX), Fruity LSD, and all the patches floating around throughout other modules in FL Studio, you have more than enough sounds. IMO you shouldn't be adding more until you really discover all the sounds you have to begin with. When you're looking for piano and substituting with sounds like the one the OP posted, you haven't even begun to dig thru your sound library.
I'm not saying every sound in the world is there, but when suggesting stuff like Nexus(not counting expansions), Purity, or even
Hypersonic I can promise you there's not a sound between those that can't be found within the stock stuff of FL.
Any synth you can think of is covered. General midi is covered. Realistic Strings, Pianos, Choirs, Guitars, ect are covered in the downloadable content for DirectWave. If you purchase the soundfont player(or download a free one) every free SF2 Library on the net is available to you.
I'm not saying you're not gonna want to add sounds, I'm just saying you're overlooking the sounds you already have available.
It's like dudes who buy Reason and instantly go looking for Refills.
---------- Post added at 09:57 PM ---------- Previous post was at 09:51 PM ----------
FL's not on my iMac right now to check, but I'm pretty sure all these are included in the free downloadable content for directwave. I know you get some good Basses, Brass, Choirs, Strings, and Pianos equivalent to this stuff.