There's a couple of routes you could go down, depending on your budget.
Cheap route, a decent remote keyboard & something like Logic (or even Garageband with some extra AUs) & you'll be playing away for yonks, but you're not gonna take this out to a gig.
Next up is a cheap "Workstation" synth such as the Korg M50, Roland Juno Gi or Yamaha MOX6/8. All around £800-£1300.
Then there's the dearer Workstations for around the £2-3k mark,
Or you could go all out & get a couple of decent modules, a keyed synth & a remote keyboard, a sequencer & a drum machine. Funnily enough, this route could be done for less than a grand, but more likely to end up spending several K.
Moog's new Minotaur looks pretty cool, add a remote keyboard or a midi bass to it & it might just be bass heaven!