ARC LS26 versus Cary SLP-05

I am trying to figure out a preamp for a system that I am putting together. While I know I may have to do some selling and swapping to get the right fit, I am trying to minimize the amount of that I have to do. Here is the system: Magnepan 20.1 (on order), Cary 500MB (500w/ch solid state monoblocks), Cary 306 Professional SACD/CD player, and amp tbd. I have a local ARC dealer (from whom I am buying the Maggies) who can arrange an in house tryout for an ARC LS17 as he has that in stock, but not the 26 which seems like is universally praised. I do like the sound of the LS17 as I heard it being fed by a dcs stack ($50,000!). Anyway, I listen to primarily classical (all sorts) with some jazz thrown in. I have extensive experience in live classical music performance (as a participant) and value sound that is musical, lifelike, not harsh in the highs, and with a realistic soundstage (one of the main attractions of the maggies). Price seems about equal for these two units on the used market. I could buy a Cary, audition an LS17, and sell the Cary if I liked the ARC better, but then I would feel guilty not buying from the ARC dealer and, of course, then the LS26 would be more $$. Anyway, thanks for any thoughts.