What wattage should I use for a switching adapter?
You calculate the wattage by the formula $$ P = VI $$ where \$ P \$ is power (watts), \$ V \$ is voltage (volts) and \$ I \$ is current (amperes / amps).

Your original supply was 14.5 V x 2.5 A = 36 W. 

Either the 45 W or 60 W replacements should be adequate.