Big can of worms. By Pro Grade, I assume you mean a greens mower (Toro, Jacobsen, Deere, Baroness) vs a powered reel mower (McLane, Tru-Cut, Cal-Trimmer, Swardman, Allet, etc.). Def sounds like a greens mower is what you are after.
Fixed-head greens mowers are the easiest to adjust correctly. Introducing a floating head design simplifies some things, like grinding, but complicates others like height adjustments and keeping all three (or more!) rollers parallel to the reel axis. Fixed head examples 25"+ are the Toto GM1600, Jacobsen GreensKing 526, Jacobsen Eclipse and Eclipse2 126, Deere 260A/B/C/SL, and Baroness LM66. I am not aware of any floating-head 26" units in a walk mower.
Electric and hybrid drive models offer on-board back-lapping options which is super convenient. The only such model that's 25"+ that I know of is the Jacobsen Eclipse and Eclipse2 126. Electric drive units (no matter who makes them) introduce the possibility of alternator or motor failure and associated troubleshooting/expense.
All walk-behind models run at about 3.2 MPH.
Toro GM1600 - Most popular by far thanks to excellent reputation on the golf courses. Clutch is a bit more "manual" which is a concern in tighter areas but it sounds like you are wide open. Transport axles are removable if desired for less chance of snagging on fences or foundations. But once removed, no transport wheels for you. Best resale value for sure - especially for cosmetically appealing examples.
Deere 260A/B/C/SL - Probably the easiest unit to find, I also see more of these listed with groomers than the others. Transport axles must be permanently cut off if they prove to be in the way. Loop handles on early models (B models especially) known to bend. It's cosmetic, but annoying.
Jacobsen Eclipse 126 - See above note about increased risk of expensive failure associated with electric drive models. Other than that, I'm actually after one of these myself. Have never seen one with a groomer mounted.
Jacobsen GK526 - My personal mower, love these especially on a non-golf setting. The controls and stupid simple drive system make this thing very easy to maintain and repair. I do prefer the newer style controls (InCommand, centrifugal clutch based), especially in a home setting as it gives a very natural feathering ability to vary speed while turning and maneuvering. Minimal maintenance needed if basic items are kept up with. Transport hubs are not really in the way so you can retain use of the transport wheels if you want to. Lots of these mowers out there, finding one with a groomer though..... they exist, but are pretty rare. Also, the GK500 series is the only machine where 99% of the parts are available from
two sources. R & R Products sold GK500 series clones for a few years so they can produce handles, frames, bedbars, adjusters, pulleys, etc. in addition to the usual wear parts like reels, knives, rollers, etc.