I have three speakers avaiable to me??

I just built mine using four of this exact 10" driver which right now includes a precision cut cabinet for free https://www.parts-express.com/morel-ultimate-uw-1058-10-subwoofer--297-130 together with the Dayton SA1000 amp and you will not find better bass on Aus!

Do you use that amp to power all four subs, or one amp for each?

After being beaten over the head with Def Tech speakers when I went to Best Buy to audition Martin Logans specifically, I am surprised they are even mentioned here.  They were honky, bright and compressed sounding.  I have to believe that the Gallos or the Golden Ears would be far superior sounding.

I too am surprised Def Tech is being recommended. Since we don’t know much about the use or room for this selection, only mentioned musical preferences - not a lot to go on. DefTEch 9060 and Triton 3+ and 5 are designed to be home theater and music speakers. There may be less expensive solutions for music only.

With what was mentioned in the original question, and from my experience with Def Tech - choose Golden Ear every time. While the Triton 5’s are very good, Triton 3’s are the (obvious to me) best choice between the three. I have no experience with Gallo (although I’ve read good reviews).

I have Martin Logan electrostats, have listened to the Def Tech 9060’s (and lower models), and Golden Ear Triton 1 (and lower models). Triton 3+’s have built-in powered subs (for the bass you want), awesome dispersion, sweet midrange (with same 'phase plug' as DefTech) and smooth highs (due to AMT 'folded motion/foil' tweeters) that sound detailed and accurate without being harsh. Just like the Martin Logan’s stats, I can listen to Golden Ear all night long without fatigue. In my home theater system, using Triton 3+, and they are great at filling the room with all frequencies including built-in dual subs. By the way, the built-in powered subs can be run from speaker wire signal or LFE input. 

Def Tech (all models including 9060) have bright, harsh, tweeters - same as B&W (to my ears) and I have B&W’s too (currently in my 2-channel music room along with the electrostats and Elac's I've been demo'ing). When I listen to those aluminum dome tweeters, can barely stand it - very fatiguing (as a side note, still like the B&W's over Elac Debut 2.0 F6.2). Some people like that surgical accuracy on the highs, others don’t. You probably know what you like. Listen to both if you can, and you’ll likely hear what I’m describing (especially if you can listen to them side-by-side or even within a day of each other).

If you have to make a rush decision between the models you mentioned, my advice is first choice Golden Ear Triton 3+, second choice is Triton 5.

I loathe Golden Ear speakers with a mad mad passion, that's' why DT was my only choice among the three.
I find them harsh ear drills with no other positive attribute. Hah!

Best,
E

Forget the above and get a pair of Quad 57's. Peter Walker's miracle and a speaker for the Ages (I have two pairs!).