Skye, those are two completely different synths. The triton is definitely what you want to start out with. Alot of people around here really like
the motif8, then some like the kurz alot, but I think the tritons are sold more than either. All three offer the same features basically. I own a kurz k2500s and I love it, but if I were looking today, I would personally choose the triton. Do you have a music store that carries those models? If so, go check them out and decide for yourself. Their all good starters.
The other synths I mentioned was a list of the most popular and best virtual analog synthesizers out today. Nord lead 2 or 3, /
access virus b, kb, indigo or c, indigo 2, c rackmount /korg ms2000 /novation supernovaII /waldorf (any) are all good choices available for a wide range of prices. For instance you can get a lead 2 for about $1000 less than the lead 3. Same with the virus B and C series. And
a supernova II or
a waldorf Q+ is gonna be real expensive.
A work station like the 3 mentioned is going to give you sequencing and sampling capability, along with tons of every different kind of sound you can imagine. You actually don't even have to have a computer to compose music on one of these. Depending on what model and options you have you may have a hard drive right in the synth or you will use floppy, zip or cd to import and export sounds. I guarantee it will take you a year to fully learn any of the three. The capabilities and possibilities will make your head swim! They are really cool. And that's definitely what you need to start (my opinion).
A virtual analog synth on the other hand is probably my favorite thing in life, and I don't even play well. Probably cuz I spend my life replying to threads like this instead of practicing.

Anyway, they unlike the workstations produce sound without samples. In a workstation sounds come from memory or samples off of a cd or sampled by the onboard sampler, or however the sample gets there, it's a sample. It's as sample as that

. Virtual analogs create sound in a variety of ways using generated wave forms in a variety of shapes or types. To make that a little simpler... It has a thing that goes "woooooooooooooooooooooooooo" or "BRRRRREEEEEENNNNNGGGGHHHH" ( my phoenetics are a little rusty ) and that sound is fed through a programmable array of oscillators and filters and modulators and efx and etc, to produce sounds that are just plain crazy sometimes. So basically the sound is made by the machine onsite rather than using something prerecorded.
Both a workstation and va synths offer endless programming possibilities, and it's really quite fun doing either. But I epecially love va programming. If you got good deals you could get the workstation and a rack unit va synth for under $2500 maybe less or just a bit more depending on what models. And that would give you the flexibility to produce all the rythym sounds, accompanying bass or pads or stings or what ever all together as well as the expressive leads, fat basses, and wild arpeggiated soundscapes that come from a va. They both do things in acompletely different way. That's why it's nice to have more than one. But I warn you, synths are addictive. The next one is never enough!
Hope that helps. Happy hunting.