I know you said you don't want to do both, but maybe you can make a necro first, level it to high levels, and then make your rogue? That way, you could twink your rogue with pretty good gear.
Also, you forgot that rogues get a DE mask from Lguk. So you can experience evil stuff too
[You must be logged in to view images. Log in or Register.]
If you decide to go necro, they aren't as gear dependent, and their gear is cheaper than a rogue's (I think?) Not that a rogue is since he's not tanking? But obviously a rogue will do more damage with better gear. Good luck deciding!