Best route is to cough up the dough for full Kontakt. It will play libraries in several formats, plus you can have a blast making your own.
The initial outlay is a significant hit to the wallet, but the purchase will eventually pay for itself because of the many free and low-cost libraries out there - that all require full Kontakt.
For example, top-tier pianos can be had for $25-$50 at Sampletekk. Or a serviceable electric guitar library or lap harp from Indiginus for $5. Or oodles of bizarre sounds from Sampleism for $5 to $20. Drum kits for $15 from Drumwerks. I've got over half a terabyte of Kontakt samples that represent a total investment of maybe $400 altogether - about the cost of one good library licensed for the free Kontakt player.