I didn't upgrade my tranny (when i had my '03 Hemi Ram) and it went out at 70,000 miles.
I did get it covered under the warranty even though the truck was heavily modded.
Here's some options, all of which we sell on Moe's.
-Transgo HD2 shift kit: $84.99, does improve shift firmness some
-Sharadon Performance Valve body: $325 plus $500 refundable core charge.
Very good and popular mod.
Should help tranny last since it makes the tranny shift faster.
-Sharadon Performance Stage 2 Transmission $2200 (i think that's right) plus $1000 refundable core charge.
Also very good upgrade
-Suncoast clutches, not all of which are on Moe's but we can get it.