Temperament is everythin and as said before, you can get all different temperaments withing a given breed.
If you get an older horse who has been and done virtually everything it will help you get your confidence.
I love clydies and have met a few beautiful quiet ones, but really just look and look and don't discount anything just because it doesn't have a big price tag or sound pretty.
You will know when you meet the right horse - I speak from experience after spending 6 months and hundreds of kilometres looking for my daughter. We also upset a few people I think by turning their horses down - and they were lovely quiet animals but if she wasn't going to get back on them, what was the point in taking them. Any of them would have done as a confidence builder but we had to find that special one - and we did.
Cost $350 and was not particularly pretty but he was the most awesome confidence builder you could ever want.
Only As Old As You Feel - Sometimes I Feel VERY Old