I know this may be too late, but...
if you are still interested I have a working MEI board that I am selling. I have the P14S-N48 board 240V, 39A (similar to number P14S-N46). My board has connected (1) - 120/240V pump, (1) 120/240 blower, a 5.5kw heater and a 12V light, GFCI not included, a broken digital topside. Note that a new P14S-N46 at Maddox cost $475.99 (includes topside).
In my opinion, digital topside controls are more prone to fail than the main PLC board. It may be more practical to spend $200.00 on a matching topside than to spend between $500 and possibly more than $600 for a controler, heater and topside.
Maddox warranty is 2 years for the topside, here is the link:
http://www.spa-parts.com/prod03.htm
Note that they now replace topsides for all control boards with the P2P model.