if I were you I wouldn't go as extreme as reining or cutting. I would start off small.
I ride BOTH english and western. Huntseat performance/equitation and saddleseat equitation/performance.
Its really a lot of fun to do both, but I pick one that I like more [i like western more] for when I feel like riding on a trail or when I feel like just playing around with my horse.
Although, its a lot of money to do both, the costs of clothes and tack are a LOT!
You can tell a gelding, you can ask a mare, but you must discuss it with a stallion.