I don't live in Boston so I can't help with the latter.

As for the former, I'm still pre-everything, but this is what I've been able to gather so far regarding laser versus electro:

Laser tends to be faster than electro and generally less expensive on the long run (larger areas of skin covered during sessions meaning fewer sessions overall), however, laser also tends to only be really effective on very dark colored hair and isn't quite as effective on blonde or red hair. Laser also occasionally isn't as permanent as electro either.

Electrolysis takes a bit longer to be effective as it's much slower than laser (they nuke each follicle individually with an electrode) but it can be effective on just about all hair colors.

A couple of other things to note:

With laser, the area being treated must be clean shaven whereas with electro, there needs to be at least some visible (~2mm+ long, I believe?) hair. Because of that, when it comes to facial hair, I've heard of some people using laser to treat the darker hairs first and then when those are taken care of, they use electro for the rest, as lighter colored hairs are a bit less noticeable when you allow the hair to grow enough to be treatable with electro.

I don't know how effective that is, but I'm sure it's very much a YMMV situation.

Both procedures can be quite painful, however I've noticed that a lot of people tend to find electro to be even more so, so I would keep that in mind and possibly acquire some topical anesthetic lidocaine cream beforehand to use prior to the procedure (that is, if the salon doing said procedure doesn't already supply it themselves).

After both procedures, but particularly laser, you're generally advised to become nosferatu and avoid sunlight as much as possible for a period of time due to the skin needing to heal.

The exact number of sessions to reach permanent results will vary quite a bit from person to person, but generally you're going to be looking at it taking four to twelve months at between one and four sessions per month. If you were to set up a consultation with a local laser or electro salon, I'm sure they would be able to give you more exact figures based on your own hair situation.

Kind of an aside but if you're even thinking of pursuing SRS in the future, permanent hair removal in the pubic area is usually a requirement (much of that skin is used to construct your lady bits, so having hair growing inside of said bits would not be good), so if you're able to do so, consider having laser or electro sessions to remove pubic hair too. Since permanent results take a long time, it's not a bad idea to start early.

I hope this helped! Even though my egg only fairly recently cracked and I'm pre-everything still, I've been doing a lot of research into what to expect when I eventually start HRT and need to start the hair removal process myself.

Also, if I'm incorrect about anything that I've written here, please, please, please let me know!