If I want to solo mine on multiple machines, do I need to have the client installed (i.e. a different wallet) for each machine?
Tried poking around and didn't see a clear answer here, is there a way to keep them consolidated under one wallet automatically?
No you do not have to install the bitcoin client on each machine. You can simply use one of the separate mining programs (i.e. poclbm) on your client machines. Next pick one of the machines to run the bitcoin server/bitcoind that itself and all your other clients will connect to. You will have just created your own pool