HEY! YOU! I board two horses in Ames too!
It's your LUCKY day!
First off- option A is NOT an option.
I boarded my mare at Stagecoach for a month. I kept telling them to ease her out onto their pasture, which, by the way, is an old alfalfa field that they did not kill off or reseed. It's 75% alfalfa, and EVERY horse there colics repeatedly or has runny stools. The pasture board may be better, but I still wouldn't. The managers, Sarah and Ann, are just awful. Ann cusses up a storm just because she can, and Sarah was just as unprofessional. My mare colicked on their pasture when I had been trying to ease her out onto it (I think they were just throwing her out in the morning without my say, honestly). The day she colicked was in the middle of finals week, and I almost didn't come out. When I did, Sarah confronted me and told me that my horse was being a "megab****" and "kicking the crap out of all the other horses." Being less than 2 years old at that point, and lowest on the totem pole, I knew something wasn't right. When I went over to her, she was sweating profusely (on a relatively cool day), and kicking aggressively at her belly. It was obviously colic. When I told Sarah, she just looked at me. I called the vet out asap. Sarah and Ann were P.O.'ed that I'd called the vet at all, stating, "We have Banamine! We could have treated it ourselves!" Neither of them are vets or even vet students, but they wanted to treat this themselves. It could've gotten very bad very quickly. (Even the vets quietly tell you to steer clear of Stagecoach.)
After that, the vet said, "Don't let her out on pasture, but put her in a paddock to keep her moving or she'll colic again." Sarah refused to let her be put in their paddocks, as she'd pushed through one of the fences before (their electric fences are horrible- I literally held the fence in my hand and barely got a buzz). And I couldn't turn her loose in the arena because the pink fiberglass insulation was exposed on the walls, and she could eat it. So after staying up all night with my mare, I had to call my Mom, who drove up from 3 hours away, to come walk my horse all the next day while I went to complete my final.
I decided to move my horse the very next day which was, coincidentally, the first day of the month. We called a friend with a trailer, and Sarah and Ann blocked the driveway with their pickups because I "hadn't paid next month's board yet." When I finally wrote the stupid $350 check, they then took turns walking close by the trailer and my skittish mare (who was not good at loading) and loudly shouted random things to people in the barn, making my mare spook and come tumbling out of the trailer. I am still going to sue them to get my money back. Mark my words. I've never seen a more unprofessional place. They are just malicious there.
I do not know of Stillwater, or Evan's stables. I know of 3G Stables, which is just north of Ames, but they're expensive and just overloaded with horses. When Canterbrooke (a very big horse boarding facility) closed, everyone had exactly 4 weeks to find a place or be snap out of luck.
Belinda is a great person. She's very easy to get along with, and everyone likes her. Her facilities aren't the greatest, and you'll have to drive to Cambridge everyday, but your horse will be taken care of for sure. I almost boarded with Belinda, but I found a little place in Ames called Clear Creek Stable. The owner is an old woman who is obsessive compulsive about EVERYTHING, but the horses are treated like gold and have pasture. You can work off your board too (starting rate is $240/month, without food or grain, and you can work off $200 of it with 20 hours of work per month; every little bit counts too- putting horses out/in, cleaning your own stall, etc.). Most people outside of the barn don't favor the owner, because she can seem awfully grumpy, but she has a reason for everything, and it's all about the safety of the horses. You just have to get used to her.
Let me know if you have any questions. I'd be happy to answer. There aren't as many good barns around here as there should be, unfortunately. It takes a while to find a good one!