Subwoofer Advice

the wireless option sounds great, do you think is a good way to go, is wireless going to be accurate match with the rest of the system? Hardwired, at least for most audio products, seem to be the preferred set-up.

In the past I had 2 or 3 of my subs connected by wireless. Ichandelier to hard wired, mostly because the transmitters I had at the time were a little fussy. I didn't notice any difference in sound quality. You don't have to connect them wireless, my thought was that might give you more placement options.  

The SVS subs I own don't have the app control feature, but I think it would be really helpful for set up. 

@big_greg ok, thanks!

Another potential for your consideration.
Just seen a review by Nemo Propaganda on youtube of the Buchardt Sub10 where it was compared to both the Kef and the SVS 3000 Micro.  Different form factor to the KEF but has a good app and a level of built in correction for less than the Kef 62.  Might be worth a look.  I confirm @big_greg's, expectation that the SVS Apps are very good. If anything the Buchardt looks more sophisticated, are very usefully the microphone set up for the room correction is done by linking it to an iphone which it uses as a mic. The results of this are noted to be as good as connecting it to a dedicated room correction mic.  Seems to be $1400 each.  Less than the Kef, about $500 more than the SVS, but suggested to be better than the SVS and slightly better than the more expensive Kef. 

@audio_rd_uk that is so funny you mention the Sub10. I just watched Steve Huff's (HiFi Huff) review of it just an hour ago...LOL!

Given your room size forget the RS-1b, they want more period ! Been there, built  bigger sold em. Moved up to IRS Beta’s…subs, not likely lol ! 
Cheers