RE: A-Jock's HC-
Hi, Michelle! Boy, that's a toughie, what to substitute for Circuit Max and HC Extreme.
For Circuit Max (at least my souped-up version, in which you perform the resistance cycles strictly with barbell squats, plie squats and lunges), you could substitute my newer mish-moshes "Satan's Mish-Mosh" and its country cousin "Beelzebub's Mish-Mosh". I'll bump up the thread entitled "Beelzebub's Mish-Mosh" on the OPEN DISCUSSION forum for quick reference. They are step-, Boot-Camp-, and floor circuit workouts that are just total nosebleeds. You may want to add on I-max 2's blasts 2, 5, 8, and 9 at the end after the Gauntlet segments (when you read the MMs you'll see what I mean); I call that little addendum "Satan's Mish-Mosh with a Tail".
For HC Extreme, substitutions would depend on which HC Extreme workout you're using; one of them is a circuit-style workout, and the other two are strictly cardio with step and floor work. For the circuit-style workout, I'd suggest either Gauntlet as produced or the Viper from the Terminator (Intensity Series) DVD. For the cardio, I'd suggest doing Low Max warm-up and blast-only premix, followed by I-max 3 blast-only premix. OR, do I-max 3 warm-up and blast-only premix, followed by the Kick Max Boot Camp challenge. OR . . .
.. .
the possibilities are endless.
I'll bump up the Beelzebub thread for you on Open Discussion. That'll give you some ideas.
A-Jock