After a lot of surfing this forum I think I'm going to go with the Cave Adventures Package and the Zeagle Rip Cord Weight System. Is the Zeagle Rip Cord Weight System overkill?
I'm also planning on sticking with the aluminum backplate and just throwing weights on it. Any issues with this?
First, Caveadventurers is a terrific place and I'm sure they'll treat you right. If the set up you're thinking of is an oxycheq mach V wing on an oxycheq plate, you do not need an STA. The mach V wing is great without one. You might have already figured this out, if so, sorry.
Regarding weight, you should decide on the plate material based on your minimum ballast needs; if you ever dive with a jacket BC and less than around 8 lbs, go with an AL plate, at least for starters, but if you always need around 8lbs or more, you'll almost certainly be happier with a steel plate. Most cold water divers need more weight to sink the exposure suit, so steel is usually preferred for cold water divers. Warm water divers that use AL tanks also usually need the extra ballast; remember you need 4 lbs just to offset the buoyancy of an empty AL80, if that's what you dive with.
I dive in warm water with never more than a 5 mil suit; I usually use a steel plate with Al tanks and vice versa. Everyone is different.
I'm not a fan of quick release weights, except in circumstances where you're carrying alot of lead and it might be difficult to stay on the surface in the event of a wing failure. I could offer better advice about carrying weight if you posted your usual weighting needs.
As an example, if you now dive with a jacket BC and 12 lbs in an AL80, you'll probably need between 4 and 6 lbs with a steel backplate/webbing harness. That small amount of weight can be easily carried in pockets on the waistband, in something like the XS scuba camband pockets.
If you're carrying a lot of weight, either a belt or a weight harness works well. This does split up the ballast between your rig and your body, which is better for people carrying lots of weight.
If you can't decide whether to get a steel or Al plate, don't worry, most of us BP/W divers end up with one of each. At least!