Would I need anything else to mount the holster and magazine carriers? This sounds like something I'd want, I've given up finding something without Velcro. Thanks.
No, you should be set after this purchase.
Just remember this is a competitor rig. It is something that is pretty heavy duty. It is not carry gear or a carry belt.
The 2 piece AA belt systems are rigid and hold shape and offer the advantage of keeping your shooting rig in one piece.
With carry rigs you typically will have to thread every piece onto the belt each time you use it.
You can compete with carry gear, and I have, but the purpose built gear is much more appropriate.