The Magic Wand is a great toy that can be used for a bunch of types of stimulation, and it's the best value on the market, IMO. We've had ours for quite a few years and both use it almost exclusively.
It's going to be more powerful than pretty much any other vibe you encounter. I see that as a benefit because you can always tone down stimulation, but you can never make a wimpier vibe more powerful. The cons are that it's pretty loud (although using it under the covers muffles the noise significantly) and the power comes in a large package. Still, it's not like the noise can be heard outside of a closed hollow-core door (at least in our house)--I've checked on that--or the size is unwieldy for most things.
Yes, yes, yes, get a package deal with at least the straight and g-spot attachments (either the vinyl or silicone, but not the jelly)! I use the g-spot one for clit stimulation as well, and we've dedicated the straight one to anal play on my husband. The vinyl ones are an excellent value and can be sanitized multiple ways (we put ours in the top rack of the dishwasher periodically). The attachments are well worth the extra $10 (or so when you buy them plus the wand as a package) because they make the Hitachi into different toys that both of you can really enjoy. There are also a bunch of different attachments now; the silicone "flutter" and "hummhim" look particularly interesting, and I bet the "triple pleaser" would be great if your wife enjoys some anal stimulation as well. In general, I'd suggest steering clear of "jelly" and other inferior materials, especially since there are lots of non-jelly attachments that look great. Make sure any attachment you get is compatible with the intended activity (e.g. you wouldn't want to use a porous material or something that can't be sanitized completely for anal play). I'd advise getting the Wand + the two vinyl attachments initially, then shopping WITH your wife (or having her shop) for additional attachments in the future after you two have had a chance to explore what your toy and existing attachments can do.
When you do get your Wand, make sure you save the box and receipt just in case it breaks within the first year. They're incredibly durable and usually don't have a problem, but my first one burnt up prematurely, and Vibratex sent me a new one at no charge. That second one has been going strong for many years, BTW, so clearly the first one had some sort of defect. It's not unusual for the Wand to last DECADES, but if you happen to get a defective product, you may as well take advantage of the exceptional 1-year warranty, right?
Good luck, and let us know how you two get on with it!