Pierods,
Are you planning on residing in Boston proper or in one of the surrounding communities? It makes a big difference because the local chief of police (not the sheriff) has 'discretion' when it comes to who gets and who doesn't get a license to carry. For some chiefs, 'discretion' means that nobody gets a permit.
The Gun Owners Action League (G.O.A.L.) used to have a page where they rated cities and towns as to their willingness to issue licenses to carry (I looked but can't seem to find it now - Maybe you can contact GOAL, they're good people).
Contrary to what many would have you believe, most towns will issue "All Lawful Purposes" permits without problems (provided you're not a felon, etc). I do know that Boston seldom issues unrestricted carry permits. However, once you get west of Rte 495, things are much different.
As far as high cap firearms go, you need a Class A to own any gun with a magazine capacity of over 10 rounds. Whether or not it's high cap depends on the gun and not the magazine. For example, with a Class B, you can walk into a store and buy a PPK but not a Beretta Cheetah. They're both .380's, but the PPK was designed for a 7 round mag, whereas the Beretta was designed with a 13-rounder. You can buy a 1911 because it was designed for a 7-round mag, even though there are high cap drum mags available.
Here's where it gets even more confusing: If you have a Class A, you can own high cap guns, but you can't buy new high capacity magazines. For example, I have a Class A but if I walk into my local gun store and buy that Beretta new, it will come with a 10 round magazine. If my local guy happens to have a "pre-ban" 13-round magazine, I can buy that too but he can't sell me a new 13-rounder. If I go to NH and buy a 13-round mag and bring it back to Mass, I've committed a felony.
In most cases it is impossible to determine whether a mag is really pre-ban, hence the wide availability of so many (ahem... wink, wink) pre-ban magazines in Mass. Some magazines, like some of the ones from Glock and Ruger, are marked. You don't want to get caught with a magazine that can be identified as a post-ban high cap.
You'll notice that I'm talking about the AWB as if it still exists. Well, it does here in Mass.
Your gun problem will be solved if you move to NH - you can practically buy an atom bomb at the hardware store there. If you live in NH and work in Mass, you'll still have to pay Mass income tax (5.75%). There's no income or sales tax in NH, but if you're planning on buying a home, the property taxes are much higher in NH than in Mass (Hey, without income or sales tax they've got to get their money somehow).
I assume that you've already looked at the housing costs around here; if not, be prepared for some serious sticker shock. The prices tend to go down as you move away from the city, but they're still high throughout much of Mass and southeastern NH.
I've lived here my whole life and have an unrestricted Class A so like FPrice, I prefer to stay and fight rather than run away. However, if you're going to move here you should know what you're getting into. The gun laws here are ridiculous.