[QUOTE most importantly where would you play/bet this horse and with whom?[/QUOTE]
Any solid out that will pay full track odds and that wagering doesn't go into the pari-mutual pool for win, place, show, doubles, exactas, quinellas, trifectas, pick three, etc. If you feel the win, place, show odds are likely to be below the normal booking level of 20/1 to win, 8/1 to place, etc. and don't plan to wager on the exotics, then more book options exist.
Releasing it to the RX could affect your odds should the race be run at a small track with a small pool. Summer tracks like Saratoga and Del Mar with larger pools might, and I say might, alter your price somewhat. On the flip side, if one wanted to increase their odds, well you get the drift.
As to where I might play it on the WPS, WSEX and CRIS come to mind. There are many others. Just depends on your anticipated odds and what type of bets you want to make. Straights and/or exotics.