Re: The Nord reccommendation:
I had a Nord Stage 76 for a year or so, 76 keys, hammer action. Its Rhodes and Wurly patches are absolutely second to none. It also comes with good B3 emulation (including a good quality leslie effect), Vox Continental, and Farfisa, all of them with working drawbars and with quirks emulated (like the B3 "Percussion" thing). An amazing live board, because everything is laid out spectacularly well - buttons and pots, no stupid menus. Want some tremolo and (good) amp simulation on your Wurly, for example? Hit a button, twist a nob, both specifically meant ONLY for those things. It's awesome.
As for its pianos, well, they sounded pretty decent over headphones. Through my rig, I didn't really like how they sounded, but in fairness good EP tone was more important to me, so I set up for that.
The keyboard action itself was a joy to play. It really felt like an instrument, instead of a fancy electronic toy. It did a few things, not 9723792 of them, but it did each one really well. Expect to pay $3000, at least, for a 76-88 key.
As for the Roland you're eying, I don't think you can go wrong with it either. I'm not a massive Roland fan honestly, but those RD series keyboards are quality.
Bass Amps:
I ran my keyboards through a few different bass heads, especially a few different Ampeg SVTs, with a 6x10 cab. Sounded awesome, very warm on the EPs. A massive pain to move all that gear though, but I thought it was worth it.
I had a newer SVT 2-PRO and I found it sometimes wasn't loud enough (300W tube). A friend of mine has a 1978 SVT and that thing is a beast, super loud.
A head that surprised me actually, was a Traynor Dynabass 800W. It's solid state with a tube preamp and actually pretty loud. Good price. Didn't colour my tone too much.
Obviously, since we're talking about bass amps and not keyboard amps, a lot of bass heads have a pretty big scoop which, of course, effs up our tone. If you can find one that's pretty flat, it'll work. I wish I knew more about actual keyboard amps, but I can definitely say that bass amps can work well. You might have to mess around with different rigs for a bit to get your tone worked out though.
Edit: Here's a picture of the Electro 3:
http://www.charmainelimblog.com/wp-c.../02/nord32.jpg
Here's the Stage EX:
http://www.performing-musician.com/p...ageEX88_02.jpg