They look like good barrels, you should buy a few for racking etc. Remember that HDPE is oxygen permeable so you have to keep them absolutely full all the time. If there is headspace oxygen will get in and nasty things will start to grow, it can happen very quickly. The maximum storage time for barrels like this is 6 months, after that the cider will start to oxidise.
You will need to bottle the cider all at once so you will need a lot of bottles. When you are making proper craft cider the logistics get more difficult because you have to do a big batch every year, unlike beer or cider from supermarket juice which is possible in small batches through the year. For the barrel you will need about 300 big bottles, what we in Australia call long-necks. I bought one big lot of bottles new and re-use them every year, I think it is worth the investment to have a standard size bottle, much easier to store. I use plastic screw caps but crown seals are just as good, I reuse the caps. Make sure you never store the bottles dirty. You can't use kegs with that much cider, it would get too expensive. I use 16gal plastic barrels for bottling, you can bulk prime with sugar for carbonation. Emptying is easier if you install a tap in the bottom of the barrel.