I have a similar setup to modder man, about 80TB in total, mining for 6 months. For five of those months, returns were barely more than the cost of electricity; the coin was full-out trash a few months ago after a massive spam attack on the network. Mining was practically impossible for 2-3 weeks while it was sorted out. That's in the past, and the newly formed PoCC is doing good work, but it looks like they're young/naive and have bit off more than they can chew, so I'm not sure if the current price will hold. My drives have paid for themselves, but just barely.
There's a lot of storage moving onto the network with the pump, so don't expect the mining calculator to predict the future accurately.
I'm basically just mining it until the next storage coin comes along, which I think is what most people are doing. If the PoCC does great things, that's great, but I'm not giving them great odds.
I haven't found a good plotter for linux, so I have a machine boot into windows to do that. Make sure your plot files are optimized, preferably when you write them to save time. One large file is better than several small files. GPU plotting is faster, but any GPU will be waiting for the drive to write the data so at best you'll get somewhere around 15k nonces per min. Seagate SMR drives can take up to a week to plot, but after plotting they're fine; just pray your machine doesn't go down at day 5 of plotting.
Linux plot readers: creepminer is the best by far, although it has some memory leak problems. Assume 1 full thread per drive for reading, at least 1 full thread per drive for verifying for best performance. 15-25 sec to scan 8tb.