The SR looks like the logical step up. Don't be in too much of a hurry, especially if you want a boat you can paddle in all conditions.
Are you able to demo both boats in choppy conditions? If so that's the best idea.
Also remember in multi sport you can be fatigued before getting to the paddle leg and when you are fatigued your balance can suffer.
My journey as a multisport paddler went
Finn Affinity (Plastic ski about as stable as V7) 6 months
Epic V10 sport Gen 1 (probably as stable as the SR (1 year)
Epic V10L Gen 1 (probably too big a step up for a 2-3 times a week paddler) ( 9 months)
Carbonology Vault Gen 1 (more an intermediate ski at the time) (1-2 years)
Carbonology Flash (Elite) (current)
In the V10 sport in some multisport races I'd overtake paddlers on elite level boats as I had the stability. From local paddlers the SR appears to be a popular ski, so cant go wrong if you buy it and want to upgrade in a year or so, it should be easy to sell. The higher you go with models the less demand when 2nd hand, so if you get the SEI and decide to step back you may find it harder to move on.
Always looking for the next boat