FiT = Feed in tariff. I entered the contract back when the premium $0.44 FiT was on offer (with retailers offering up to $0.52) and was available for up to 30kW. That has changed and is no longer available to new installations.
10kW was the larger made in 3 phase by Solar Max as I recall. Either that or they were cheaper than a single 30kW unit. I guess the benefit is that if one fails, the others will hopefully still be working. I had one of mine fail just months old but they gave me a complete new one and I have not had an issue since. I particularly wanted Solar Max because of their history and Swiss precision so I must say I was none too happy when one failed, but it seems that was just a one off and unlucky for me to get it as they do have pretty good reliability and a 20 year history to boot, but their parent company apparently went belly up in 2014! I've been meaning to follow up on that, but haven't needed to so far and do believe they were bought out and back and running again.
As for the micro inverters, I did consider that option however two things stopped me. First, electronics can fail and the micro inverters didn't have much history so it may have been an expensive mistake if 150 or so inverters (which were also more expensive) started to fail en-masse. Secondly, each micro inverter mounts under the panels, so if just one or two fail in the middle of the bank, it'd be a real pain to get to them to replace. For me, it could mean disassembling maybe 50 odd panels, which doesn't interest me that much, however if no failures, or they're set up so they're easy to replace like in a ground mount installation, the logic behind micro inverters is sound.