There are 2 different trains of thought with the prospects you posted. There is the "dreamhorse" group, which are pretty well started, and you are paying for it, even though several most likely started in your second group, the OTTB group. You need to decide which group is for you. Only YOU can decide that. THe OTTB's are great, but you will not know what you have out on the trail until you try it. Most horses will be fine with miles. Yes, there are a few who are naturally spooky, but those are not ones you will most likely pick anyway, since you are looking for "quieter". Some depends upon the time and effort you want to put into it, and you have to be realistic with how much time you have to train a horse. Again-only you know that. THere are really only 2 in the group you posted that I would not think would fit your needs-the pally, who is lovely, and I am partial to QH's, but I think you would probably get frustrated trying to get the dressage part of eventing done on that one. I also would not even give a passing thought to the one OTTB who IS adorable, but has an old slab fracture. Different story if you were just trail riding, but the fact that you want to jump-no.
THis is certainly the time of year to buy the OTTB's. THe tracks are shutting down for the season. Shoot-a friend of mine got a drop dead gorgeous grey last week at Charlestown....FREE. Sound, nice prospect. She just went to help a friend pick up a horse, and was offered this one. SHe is also in MD, and has gotten 2 others at Camelot Auction, both of who, she has put a few miles on and resold.
I am currently in NY-the track here has a rescue as well as trainer listings. I am about 5-6 hours up rt 15 from you. Easy drive. Here is the site. Finger Lakes Thoroughbred Adoption Program Home
THis is the main rescue site. In the column on the left are the trainer listings. There are MANY more horses there. I will also put the word out if you want. My friend and BO is sometimes offered them free at the end of the season, and many are really nice prospects. SHe has had hers for years, and another friend of ours got hers that way. Sometimes some go unlisted.......
I would also suggest you ask Star, or your trainer. She has been doing this a LONG time, and I regret her not helping me when I bought my last Hunter prospect. Now that I do reining I use my other resources for an extra eye (and an objective one).
GOod luck! Let us know what you find!