John,
I think you have more than enough strobe power with the 4 Photogenic lights and, since you are familiar with them, you'll have no learning curve. Good choice.

Studio rental is an interesting option and it'll give you the space you need to do some set-building. That's good. It also increases your overhead. That's bad . Such are the trade-offs.

I like the idea of a raised "stage" so you can have a little breathing room for low shots. I think you'll really appreciate that addition when you shoot larger breeds.

Let me know if you need any help setting things up or building the stage. I have tools, can travel and am reasonably handy:).

Cheers,

Jim