I really like the way I did it. I won't need the chain slider once I re-gear to something like a 45t in the rear. I find it easier (and looks better) keeping the stock puch swingarm and wheel. More gearing options. Of course it takes more work lining everything up, but overall I'm very happy with the setup. Ultimately you get a much more stable bike through turns because the swingarm pivot point is closer to the rear wheel. Flat reeds in their stock form (with the swingarm attached) have a lot of flex and aren't confidence inspiring, even with the rear stabilizer.
My buddy did it with a derbi swingarm on a garelli frame:
He uses the lomat 4 petal and a custom intake. Everything fits great. He swapped to a puch rear wheel after his derbi spoke wheel failed on the track.