Confused about your question. It's impossible to replace the stock bose amp without splicing wires. It can easily be done, as long as the wires are cut/spliced.
In your case I'd recommend a nice 5-channel amp. Just so you know, the bose speakers are 2-ohm speakers, so when you get an amp look at the 2-ohm power because that's what the bose will receive.
With a 5-channel, you'll only be installing one amp to replace the bose, and have an extra output to power a subwoofer. Sound good?