BulletMaker,
I really like the idea of 3 fans (same as DB offroad and yours). Not trying to convince you to go with it by any means, lol, I just think that 3 efan is the best way to cool off the wide and short radiator xjs have.
Regarding ease of work, the frame DB offroad built is relatively sturdy and won't bend unless you really want to bend it. Without pushing the radiator towards the front of the car I still have a comfortable inch between the fans and the pulley where the viscous fan was installed (measured where the nuts from the old fan are, you could also get a little more than 1/4 inch extra clearance if you cut the nuts since without the viscous fan mounted, they don't need to be that long). Pretty much I didn't do anything other than installing the DB fan bar. I also took about 1/4 inch from the long bracket (using a grinder) that sits on the top of the radiator, not that I had to, but I wanted to allow the fan shroud go more towards the radiator (as the long bracket sits on the radiator, I grinded the part that goes down, towards the radiator - sorry, I'm not too good explaining but I can take some pics if you think it can help). I also have a 1 row radiator, a 2 row radiator shouldn't be wider by more than 1/2, maybe max 3/4 inch compared to the 1 row, but only half of that extra width should go towards the engine, since the other half goes towards the front of the car/ac radiator. On the DB shroud, I used the supplied 2 brackets to secure the top part of the shroud on the long bracket that sits on the top of the radiator. To secure the lower part, I just used 3 sheet metal screws from Home Depot that I had and that go freely through lower radiator brackets where the old shroud and fan used to sit (your designed shroud is definitely a better solution, but I didn't feel like wasting too much time, so screws worked fine for me). To take the DB fan bar out, I only need to unscrew the top 2 screws and pull the fan bar up. Either disconnect the fans before, either cut the cable ties that secure the fan cable on the front on the car (which I just did few days ago when I blew up the radiator by being lazy when installing the thermo coupling for the radiator - the one that starts the fans when the temp reaches whatever value). In few words, replacing the radiator was a very easy task. I also have a tranny cooler mounted in front, that also gets cooled by the efans. I completely deleted the stock tranny cooler from the water radiator and I can say that in almost 20 k miles the oil for transmission looks as new, before I had discolorations due to operating at high temperature.
The way I have it set up, as electrical wiring, is this: 2 relays are connected one to center and one to passenger fans. I have a switch in the center console (inside the car) that gets a plus from the cigarette lighter (since its only on when you turn on the ignition and I don't use the lighter anyways, so I won't risk blowing the lighter fuse and have no power to switch on the fan relays). That plus goes to both center and passenger fan relays through the switch, so you can turn it off also when you go through high water, etc). From the battery I have another plus for both relays (and ofc fuses for each). Now, in between the switch plus and relay plus (the one that starts the fan, not the batt plus), you can insert the thermostat, so when the temp gets to a specific value in the radiator, the fans will start (of course as long as the console switch is on). This lets you turn the fans off when you want, and also prevents engine from overheating/running the fans for more than necessary.
The 3rd fan (driver) will be also connected to a switch in the center console, so I can start it when I feel like, but right now I hooked it up on the factory efan wiring. I live in Cleveland, it's cold here right now so no rush.
The thermo coupling that I use is a cheap 20-ish bucks from autoparts, this time I inserted the probe in the lower hose that gets water in the engine. On 20-30 degree weather that we have right now here, the 2 fans start for about 10-20 secs, they stop for about 30-60, and start again. This is with engine warm at idle. I still need to see how they will work in 100+ degrees, but I really don't foresee any issues with all 3 fans running, as long as they won't break, which will definitely suck... This is my only concern in regards to DB efans, I don't know how reliable are those fans.
Bottom line is that choosing in between all efan conversions available that I know off, the DB model is the best IMO. I also got a 13 in fan, from 4wd, but that required modifications that I didn't feel comfortable doing, including getting a different belt due to taking out the stock fan pulley.
Sorry for this long post, just thought to lay out my opinion and limited experience for whoever finds it useful.
