The X-Lock Cobra series looks promising bringing a modern option offering a design with lessons learned from issues of other male chastity devices out there.
Gag enthusiast Kitty Denied tests out a ball gag harness from Bitches Love Leather and discusses all of the details that make their unique spin on a classic design something any gag fetishist can appreciate.
Although the iQ-Plus unit seems to be a great starting point for most, for more strong willed submissives I've investigated into making a new wide version of this collar to accommodate the Dogtra 2300NCP.