Good sushi rice is the most difficult thing to make. It really does take practice to even approach what a good sushi bar dishes out. Perfectly cooked throughout, just enough stickiness to stay together, perfect sugar and vinegar seasoning, a slightly chewy texture.
Get good sushi rice. Common American types would be californian calrose.
The rice must be washed to remove the powder which is usually a mixture of ground rice, grinding compound, and minerals if it's "enriched". Usually requires 6-8 rinsings in my kitchen (takes about 15min).
Get a rice cooker. Walmart has them with nonstick bowls for about $15. That will save you a lot of grief when first starting out. Otherwise you have to be careful not to stir and guess when all the water has been evaporated/absorbed along with heat settings and rest periods.
Different amounts of rice require different levels of water do to surface area and evaporation within the cooker. The age of the rice also plays a role. Old rice is drier, and requires more liquid. It will take some experimentation to figure out the perfect ratio.
I let the rice sit in the pot/cooker with the water for 1/2hr. This allows the rice a chance to "open up" or "flower". It prevents the common hard center mushy exterior rice problem and reduces the amount of required water down to almost 1:1. After cooking, I let the rice rest in the pot for 5-10min off the heat just to help reduce the temperature a bit which stabilizes the rice somewhat.
Next, it's tossed in a wooden bowl/tub with the vinegar/sugar mixture. Be sure that it's unfinished wood, as you want to absorb any excess moisture. This helps with that perfect texture. Most sushi bars skip this step because it requires cleaning the Hangari every batch of rice. You know a good sushi bar when you see the chef (or his helper) using a hangari with a table fan set up to cool the rice. Good rice looks like glossy pearls, but the gloss is not moisture - it's a smooth exterior that has dried slightly.
I sometimes just make a few balls of this sushi and eat it plain with some miso soup and pickles.
For you, I'd recommend the following.
1. Ditch the brown rice idea.
2. Get a rice cooker.
3. Practice, practice, practice, practice, practice...