Things like the ESP can't be added later on without the parts and labor expense on the scale of what an entry to mid level Bennington would cost.
That being said, you'll need to really take a critical look at the typical conditions that arise on your preferred BoW(s) that you will be boating on.
If you plan to take a whole host of folks out, will you be wanting the extra buoyancy for getting "just one more person" aboard, comfortably (and legally)?
Do sudden weather conditions cause rough waters to flare up with little to no notice where that extra buoyancy may come in handy for getting back to port safely while pegging the binnacle in the WOT position?
According to the Bennington website, each elliptical pontoon adds around 1,000 pounds of buoyancy over the standard round pontoon (does not specify if this is compared to the basic/value 23" or the standard 25").
If you have the budget for it, then go for the ESP...the extra resale retention value can't be argued with since it's a highly sought-after bullet point in the used market for very discerning shoppers knowing what it is and what they want, specifically.
But, if saving money is the concern, then money saved is money saved, so the SPS becomes the front-runner...and it's still a Bennington, so the resale value will be there.
This is my personal take, so take it as the giant grain of salt that it is: If it were me and a budget limit would make me decide between the SPS with a VF250 or the ESP with a VF200 (both are the same 4.2L and both using the recommended Yamaha Saltwater II 15.75x15 prop with only a 2-5 MPH top speed difference in the full range of 40 MPH arena, then I'd probably opt for the ESP and VF200 and live with low to mid 40 MPH speeds as compared to VF250 with mid to high 40 MPH speeds for a boat the size and weight of the 23LSB.
When that engine warranty runs out, then there are some beautiful things that can be done to the 4.2L series...one of them being as simple as swapping out the Engine Control Module since they are identical engines in just about every other aspect:
Engine Comparison | Yamaha Outboards
MSRP comparison for the 23LSB (pontoon package, engine, and dual batteries only - *no other options added*, for comparative purposes)
SPS+ with VF250: $78,703
ESP with VF200: $78,756
Yamaha Performance Bulletin examples:
PB_BNT_2375RCW_VF250XA_2014-09-30_PNT | Yamaha Outboards
PB_BNT_2375GCWA_VF250XA_2015-08-18_PNT | Yamaha Outboards
PB_BNT_2275RCW_VF250LA_2012-05-14_PNT | Yamaha Outboards
PB_BNT_2275RCW_VF200LA_2012-05-15_PNT | Yamaha Outboards
Again, if you have the budget, then get the best of both worlds: ESP and VF250.
Good luck with your decision and a preemptive congratulations on your new Benny!