You could get another Vci100, or just upgrade your controller to the 400 if you’re really feeling VCis. I can’t go back to 2 deck controllers anymore, just seems there is so much more potential with 4. As far as a sample launcher, you have a few options…..
You could go for a maschine/maschine mikro, and integrate that into your kits, or you could get a midi fighter and learn to utilize traktor’s remix decks (or an f1, and this assumes you use traktor), or you could get a launchpad and start integrating ableton into your sets. Hell, you could get a usb synth and map it to shoot samples…….. I personally enjoy the maschine of all the aforementioned options, for velocity sensitive pads allow for finger drumming as well as one-shotting.