Amp for stock Bose system?

Just bought a 2002 3.2 TL Type S and I love it. I'm looking for advice on whether the stock Bose speakers can handle an amp & if so what is recommended (how many watts can they handle, ohms, etc?). Also thinking about adding a single 10" sub in the trunk, not looking for pavement-rattling bass, just clean crisp sound. Thanks for the help!

P.S. Also wondering if I upgrade the rims to 18"s if it will upset the way the engine, speedomoter, suspension, etc. function? It currently has 17"s on it.