I got some T-Rex springs for my 2004.5 3500. I will post some pics soon.
This raises the front 2.5 to 2.75in. Stock shocks are fine.
You can run 315's easy with this set up.

 

If you just want to level the truck you can remove the lifting blocks under the rear springs for no cost. They look great this way. I did it and am running 315's on H-2 wheels. No rubbing, no problems. Also, I installed Rancho 9000 shocks. The catalogue doesn't show them but they are available. Very good shocks and much better than stock!
If you want to keep you truck at or near stock height, and run 315's, the H-2 wheels are the exact right size and offset. They work.
Wetspirit

 

Thats correct. I have 100% stock suspension and am running H2 wheels and 315's... No rubbing and they look great.

I just ordered the Revtek kit from http://www.rockymountainsusp.com/dodge4_03diesel.htm
It comes with aluminum spacers and new studs for $122

 

I put on leveling kit from JackIt on my 03 - I think it is jackit.com
I've ordered a lot from them over the years and always been impressed
Their kit has the steel spacers w/ hardware and new shocks for $199
I know everybody says you can use the stock shocks but, to be honest with you my truck now rides BETTER than it did before and the only reason it could be is the new shocks might be slightly softer
I rode around with the stock 265s about as long as I could take it (2 weeks) - it looked ok but it will scream for bigger tires - I put on 33x12.50x17 mud terrains and to be completely honest I should have gone with 35s but oh well
No alignment needed!! - You wont be dissapointed but, it may make you want to go higher!!

 

I had Superlift 2" springs and shocks installed up front and am fairly pleased. If I had to do it again I would go for Skyjacker 2.5" springs which I think would help with the Ranch Hand because the rear still sits noticeably higher.

 

I went to Les Schwab tire and they did complete install for $30.00 more than I could buy the kit for. so why do it yourself

 

There's lots of the kits on EBAY I got mine for $99,used the stock shocks and only aligned it to straighten the steering wheel. I have used several diferent companies in the past have noticed no differences. I would however stick with the steel kits though. Yes, the 03 will work on the 04 in fact the 1/2 and 3/4 ton are the same. Look at most of the popular websites for liftkits and the part numbers are the same.

 

You can get the Skyjacker replacement springs from Summit Racing for $149.95. Their part number for them is SJA-D25. The Summit description shows they are for Rams through 01, but the Skyjacker site shows them to work with current models.

-Muzzy