The MJVO-3 is a great valve, but it's really only useful for very specific builds of homemade airguns. You couldn't just "substitute" it into a build where you were going to use a ball valve as a trigger and have it work. It sounds like you had a specific design direction in mind; do you mind sharing details so we can better help you out?
I would second Blitz's suggestion of the Mad Ghost design using a PVC check valve, though, if you're not dead-set on something specific yet. There are also solenoid valves (like the one used in cxwq's BAMF design) that have manual bleeds that work like a ball valve but are much more ergonomic.
I've mostly been looking at http://nerfhaven.com...ade-airgun-v10/ Which is your build Ice, but i haven't really built anything myself yet.
I've been drawing and thinking of ideas because I'd rather not spend money on something that won't work.
But the QEV blaster and the Madghost seem like what i want to make, which is a compact but decently powerfull air blaster