Maybe this is overkill?

(www.amazon.com/dp/B009IAP5OE/ref=cm_sw_r_apan_i_ERW8BWN49R3TMTQXDNDZ?_encoding=UTF8&psc=1)

the RMS is only 15 watts (at 4ohms)on that - the maximum output is 300watts - which really means nothing. Maximum output is a theoretical measurement, never will be seen in real world applications. So find an amp that puts out between 50-150 watts... might be a little bulky, but try this one (it's also four channel, but it was a quick search) https://www.amazon.com/Pyle-Hydra-Marine-Amplifier-Waterproof/dp/B009IAP5OE/ref=dp\_prsubs\_1?pd\_rd\_i=B009IAP5OE&psc=1