Hello Everyone,

As I moving up the waiting list I am wondering should I change my build. Room size is 15'11" X 19'6" with a 8 foot ceiling. My order was for the MK 5, but the speaker that I plan to get is the Martin Logan ESL 13A which seems to be more power hungry than the specification of the MK5. Does anyone with similar setup? I am not a loud listener typically under 80dB. Of course numbers don't correspond with actually listening experience, but once the amp is build I won't able to go back to change to build.
I was looking at the Pass Labs AB amp option as well. That is why I am kind in a dilemma right now. Any opinions or experience greatly appreciated. Thanks.

I'm not going to give you any theoretical math on what or what shouldn't have good synergy with your ML's and a Torii MK.5 amp.
But I do have a Torii Mk.3(with Decware upgrades) that I've had for many years now(love it - will probably never part with it) and have tried out with dozens of different speakers.  
I have owned three different Martin Logan speakers over the years.  I currently have a pair of ML Vista's which have a slightly smaller ES panel than your ESL 13A.  The Vista panel is 9.5" x 40" where the ESL 13's panel is 13" x 44".  You also have 2 powered 10" woofers and the Vista has one 8" passive.  The Vista's and your 13A's have the same 91db specified sensitivity.
Long story short - My Torii mk3 Does Not drive the Vista's well - at all.  The Vista's need a lot of voltage, as do most ML electrostatic panels IME.  The Vista's are pretty lifeless driven by the Torii 3 at any volume.  Now... put the Torii 3 on "any" of the numerous crossover-less, full-range single driver speakers I have, and that combo will spank the pants off my Vista's driven by any amp I have ever tried.  Amongst my audio buddies, when they first heard my Torii/full-rangers compared to my Vista/big solid state amps, one of them dubbed my Martin Logan's as the "Slow-gans".  The crossover-less full-rangers/Torii combo's have so much more life and micro dynamics, especially at low volumes.
I also have a Cary SLI-80 SE tube integrated, at 4x the power of my Torii 3.  It does not drive my ML Vista's the best either.
Before you drop large coin on an amp, I would really recommend you try that amp driving the speakers you intend to pair it with first.

Come on up to the Decfest next month and listen to some combo's.  
I attended my first Zenfest in 2012 after getting bit really hard at RMAF by a demo of a flea-watt single ended amp driving single, full-range driver, crossover-less speakers.  It literally changed my life, after 40+ years in this hobby chasing the holy grail...

I guess my question is, is your heart really set on the Martin Logan speakers?

I had a pair of Sequel IIs long, long ago and they were great speakers, in the right room with the right amp, but they needed a lot of watts. I don't claim to have any insight into how the 13As will work with a Torii, but I agree with maddog that there are any number of great speakers from makers like Omega, Caintuck, Decware itself and several others that are sure to sound outstanding with any Decware amp.