Ok forgetting everything else...which horse do you feel the most bond with? Since you are going to be pleasure riding you want to enjoy the time you spend with your new equine partner and the bond is probably the biggest part of this. Height and breed really don't matter as much as the bond. Which one would you rather hang out with for three hours? That is what you will be doing on trail rides. Personally of all the horses I have owned I really do preffer mares as I tend to bond with them so much more strongly but alot of people find the opposite or that it doesn't matter which.
What does your gut tell you when you look in their eye which one makes your heart swell? That for me (provided the horse meets the requirements of what I'm looking for which it sounds like both of these do) is the most important factor!
I'll be interested to know which one you pick :)