I've found it very easy with the boil kettle (larger pot with the ball valve installed) smaller pot (20qt cheap pot to heat the sparge water in) and single large cooler. I simply mash in the cooler, heating the mash strike water in the kettle (usually more than the smaller pot can handle), mash in, then heat up the sparge water as it gets closer to when that will go in. I just drain the mash into the kettle, cover and wait for the sparge to complete before draining that into the kettle too...
Also means I only have one cooler to cleanup too. I have also found it's easier to fit ball valves into pots than coolers. Also means I can leave the kettle on the floor while I mash, and sparge, then just lift it up to the burner when it's all collected.
I would go with a more basic setup initially, using what you may already have on hand as much as possible. I picked up the 20qt pot for a discount (dented) from the LHBS. Made my own kettle from a 32qt aluminum stock pot, and converted a cooler I already had into my mash tun. If your cooler is already large enough for your mash sizes, then convert it. If not, then you'll want to get one that is large enough. For the amount of time the mash runnings will sit out of the cooler, and off of the heat, it's really not necessary to use a cooler. Well, unless you're in Alaska, and/or it's in the middle of winter.
Look at hardware this way, you really don't need much to do the job. A large enough pot/kettle to do your full batch boil, a cooler, or MT (or nylon bags if going BIAB), a second pot is usually very helpful, for either BIAB or when using a cooler MT. You could get away with using a bucket to hold the mash wort, while you heat the sparge water (in your kettle)... I would advise either getting, or making, a wort chiller. I think a lot of people start off using IC's, since they're easy to make, and not too expensive, plus easy to use. Some people change over to either CFC or plate chillers later. It's just a personal choice. They'll all chill your wort quickly (as long as you have a decent source of cooling water), far faster than trying to use a cold water/ice bath method.
Since I've started using the kettle (pot fitted with a ball valve) I can't imagine not using one. Yes, you can use an auto-siphon to get the cooled wort into your fermenter. But, with the ball valve, it makes it far easier, and much faster. I think my last batch drainged into primary in all of 1-2 minutes (if that). If you're at least a little handy, you can make/modify a lot of your own brewing hardware/gear. If you don't have the time, or would rather just buy it already made, you can go that route too. Again, more personal choice/preference than anything else.