Best Rx stimulant for long term and long lasting use?

[AbusedTampon]

So I'm looking for a pharmaceutical stimulant that is best for it's effects lasting 6-12h and, hopfully, the one with the least harsh crash/come down. I'm not looking for a magic stimulant, I know with any stimulant that lasts a long time that there will be a significant come down but which is the softest?

And also which one can be used long term, up to a year with the least amount of withadrawl. My expectations aren't crazy I know that there will be withadrawl and come down with any stimulants but with the variety of pharmaceutical stimulants I'm more than sure there's one better than all the others.

Oh and, I'm not looking for recreational effects, IMO using Rx stimulants recreationally is near impossible and wastful as you end up almost being forced to be doing something productive.

 

[dopamimetic]

Rx... this is difficult because the best ones aren't available by prescription. If this is the limitation, then probably Concerta or modafinil.

Isopropylphenidate.
Pemoline.
Maybe 2-F(M)A.