Personally I would try to at least step up to a reefer 170. Its not that much more money and having a sump will make life so much easier. You have room to work, AIO are ussualy pretty cramped. You have room for a traditional skimmer vs hob, place for heaters, fuge if you want, more rock if you want less in the DT. I could go on but you probably get it.
I had an AIO that worked but was a pain working in the back chamber. I gave it away and stepped up to a reefer 170 gen 1 and been happy with it.
Nothing wrong with an AIO of that is what you want but I would only do it if I absolutely could not have a similar sized tank with a sump.
I also have a reefer 300 g2. The plug and play plumbing that comes with the redsea tanks only requires assembly and is pretty easy. Ive done diy plumbing also but do not really like doing it. JMO