First and foremost, you need to know how much and where you will be anchoring. If you might anchor 15 days a year, within 50 miles of home, then you will want the kind of ground tackle most are comfortable with in your area. If you are going cruising, then a more versatile set up may be better.
It is a total fallacy that high tensile or g-40 chain is better than BBB. 3B weighs more per foot than either (shorter links=more links per foot) and it is the weight of the chain, not the strength that is important. For the same reason, I would use 3/8" chain, but as mentioned above, it really is a matter of what gypsy your windlass can handle.
I've been using a Rocna for quite a while now (1000+ days) and it does exactly what an anchor is supposed to do, perfectly. I've not used the Manson or Mason, but I'm sure they do just as well. From what I see around me here in the Caribbean, no other anchor does as well as these three, period.
If it was I, I'd get the appropriately sized Rocna, Manson or Mason and at least 200' of 3/8" 3B hot dip galvanized chain for my #1 anchor set up (even if I had to get a new gypsy). I'd move the plow to the #2 with 50 or 60 feet of 3/8" chain and 250 to 300 feet of 3/4" three strand nylon line. If you can afford a Fortress for your #3 (stern?) anchor and much the same rode as the #2, otherwise just a Danforth of the appropriate weight would do fine.
On a 45' boat, a power windlass is an absolute necessity, unless you are built like a WWF wrestler. I've seen too many people put their lives and vessel in jeopardy, having a manual windlass in a situation where a powered one would have had the anchor up and them gone, instead of still winching away as they are dragging down on another vessel or the bricks.
I may be a bit obsessive about my ground tackle (and dock lines), as my signature indicates, but better safe than sorry. However, I do put my money where my mouth is, as we have just up graded from 3/8" 3B to 1/2" 3B and a new gypsy to handle it.
Just my 2 cents to get you going.