Mr. and Mrs. Ellegua on your new bikes!
You both made sporty choices, I think those two bikes will match up nicely together. You're a lucky guy to have your wife as a riding partner.
Personally I don't go for the extended warranty or the prepaid services, but then I'm an old hand with a wrench and I do all my own maintenance and repairs.
If you'd like to learn how to work on your own bike, I can tell you it is a rewarding experience, and gives you confidence in both your mechanical skills and your motorcycle. Having a new bike is a good way to learn because the first services are simple oil changes, bolt tightening, and chain adjustment. As your bike gets older, you progress with the repairs as things wear out. Makes for an intimate relationship.
As far as the warranty, a lot of dealers are real sticklers about warranty work and will use the slightest excuses to charge you for repairs even if you are covered. Some dealerships don't employ the best mechanics, and some are not altogether ethical. How much do you trust your dealer and their mechanics? Do they have a good reputation with other customers?
Also keep in mind the warranty does not cover normal wear items like tires, brake pads, cables, hoses, chain, sprockets, etc.
The things that make it worth it is if your computer goes out or you have catastrophic mechanical failure in your engine/tranny, or chassis component failure caused by manufacturer defects. It happens... not often, but it happens.
If you decide against the prepaid service agreement and/or extended warranty, that's a lot of money you can spend on accessories, like your racks and cases.
There's a lot of aftermarket gear already out there for the SV, and more is coming out for the B1250 all the time. Also, Suzuki has their accessories for both bikes. If you are buying on the finance plan, you could put all that stuff on your financing. Genuine Suzuki gear usually gives your bike a better resale value, not always so with aftermarket stuff.
Just my 2 cents... make the choices that are right for you and your wife.
And
to the community... ride safe, ok?