Good to see you are still kickin'!
Hey, I forgot about SVS's great upgrade plan!
Honestly, I would buy these for the surrounds and return the Primes since you have that option!
I'm not saying that these are better speakers than the Primes, but this is one of those deals that you aren't going to beat, and it wouldn't surprise me if they were every bit as good as the Primes for the performance needs of surrounds (since they were designed specifically to be surrounds instead of a full range speaker):
https://www.amazon.com/JBL-Bookshelf-Surround-Speaker-Special/dp/B01EYJZYQ2/?tag=dealnewscom&m=ATVPDKIKX0DER
$79/pair on closeout from $199/pr!
Note that this is a sealed design! All you need is a screw in the wall (and maybe felt for the back, but I suspect JBL provides some type of pad to prevent vibration).
Also this is a closeout - they won't be around forever. Also Amazon Prime, so easy return if they don't work out for you for some reason.
Hopefully that will save you enough money to get those Ultras sooner rather than later!