Here are two suggestions for either iSDT Chargers:
SC-608 - it's easy to buy an old laptop brick of 120W@19v or something... just change the plug for an XT60 and you done! (I had one lying around)
SC-620 - this one needs a beefier PSU. I'm using an HP 725W Server PSU, you can find them in e-bay for very cheap prices. With this one, I will be assembling a rack with one SC-620, one Q6+ and two SC-608, all connected to this PSU. (yes, I know the 4 of them working at full power would largely exceed the 725W of the PSU, but I just want the versatility of having 4 independent chargers, and I doubt I will ever reach the PSU rated power.)
I already owned both the D100 and the Q200, and IMHO the user interface of the iSDTs is way better. The iSDTs are also much more efficient in balancing battery cells (the SkyRCs can sometimes waste a lot of time trying to do so in the final milivolts, without ever being able to do it effectively). With 6S batteries or even with very large 4S batteries, you are limited to slow charging (charging a 4S 8000mAh @ 1C exceeds 100W limit per channel of the D100 or the Q200).