I would suggest talking to a trainer because they will know for sure what horse you need. Bigeq is where I bought my horse its very good for finding equitation horses.
Talk to your trainer about what you want in a new partner. If you want to do some searching by yourself, I often use ProEquest and BigEq, both online horse shopping pages. There are also Facebook groups that share sale horses.
I'd talk to your trainer because he/she likely knows of some possible horses near you. When you try a horse make sure you ride him/her as much as you can before making your decision:) Good luck!!