That board will let you do that, so that's not a prob. Parallel charging 6 2S 5000mah lipos is the same as charging a 30,000mah 2S lipo.

You don't have enough charge rate with either charger for a 1C charge rate of 30amp. You could charge at 20amps, but it would be slow since it would only be .667C and would take approx 1/3rd longer tha a 1C charge.

Power wise, a 20amp charge of the combo would be 168watts, so you would have the power to do it with either charger. At 10amps, it'd only be 0.5C and you'd be looking at charge time of more than 2 hours.

You could charge a single 2S 5000mah at 4C (20amps) and it'd take 15-20min - as long as the lipos are rated for charging at that high of a charging C rate.

If you're serious about the 6 in parallel, look at a 30amp charger like the iCharger 306b, its max rate is 30amps and with the right power supply, it has 1000watts. The 40amp FMA Powerlab 8 would be even better, but its even more expensive than the 306b.