I been watching videos but confused on which one is better?, one is a sampler but you can still sound effects box and the other is a sound effects box with more synths?. Are the effects much cop too?

I'm not sure which KP3 or Pro is better next to a SP?, or should I wield dual SPs

I think a synth you can sample and make some small loops on would fit my personal needs. Pro has lots of synths and sounds built in you could sample into the SP.

Go the original KP3 (2nd hand) over the Kaossilator Pro or KP3+. You'll spend less cash & you'll get a very similar device to the KP3+.

The Kaossilator Pro isn't much of a synth, Korg mucked up an interesting opportunity with it. It's basically a preset device (you can't make your own sounds in it). You can't easily play pitched notes on it and the screen's single touch-point only (you can't play your own chords on it). If you want a synth there's heaps of better options in the same price range (2nd hand Microkorg, Akai Miniak, Novation Mininova).

The KP3+ does have a few more patches than the OG, but the price isn't worth the difference (to me anyway, you might prefer the KP3+). Even though the OGKP3 & KP3+ have synth patches they're super limited & sound lame (they also come with the same issues as the Kaossilator Pro).

Think of the OG KP3 as an effects unit with bonus sampling & it'll treat you well. The effects are heaps different to SP's- for instance there's more than 1 reverb, different kinds of filter, 8-band EQ, LFOs etc. IMO an SP+KP3 combo is nicer than 2xSPs (I got 2xSP-606 & an OG KP3)- the different workflows compliment one another in a way that'll get you thinking more creatively.

You might have interest in this model as well.....4 different effects you can use at once, no Midi, and you can keep effects on if you wish (meaning you don't have to trigger them with the pad if your hands are busy with the sp)

Run a SP into a KP3 and midi them up; you'll have a perfectly synced setup and you can loop into the KP3 like a ghetto 4 track, and have the effects to add on top (plus you could have say 4 different effects on the 4 tracks/pads)

The Quad is fun too, but is more of final-link-in-the-chain deal, or something fun to put after a synth before it hits the SP inputs...I use my quad between a novation x-station and my interface and it adds a good deal of character to even boring VA type patches.