jbridge is the one most people use - I have it on my Cubase system for just a couple of VSTis I can't upgrade, but Cubase and quite a few popular DAWs, plus score writing software really need to be kept up to date. Kontakt 5 is now quite old and as I keep adding more packages, the number that work on 5 are reducing. All my latest ones need the later version, and only this week I needed to upgrade again to download the latest package. Sibelius is constantly updated and even if you get a bridge working, there is no guarantee how long they will stay working. Cubase needs 64 bit or it gets cranky - so you're going to have to really think about a general upgrade. Everything else is a time limited bodge.