What was said is perfectly correct. Boosted single battery design draws large amounts of momentary current from the battery, and the IMR is the best suited for this application. IMR batteries can stand up to 20 Amps of current, which is enormous. Moreover, when they fail, IMR batteries do not explode, they just get very hot. The IMR batteries are not protected because they are designed for high current applications and are relatively safe when they short out.
In a purely mechanical mod, without electronic protections, you might consider protected ICR batteries, but there's a lot of debate there as well - if that tiny piece of circuitry on the battery fails, the results are catastrophic, whereas if you were using an IMR battery that would happen would be massive current dump and heat - still pretty bad, but no boom. Another option is to use the
Vape Safe fuse with any battery just for an added layer of safety.
Batteries are like a box of chocolate - you never know what you're going to get. It's best to stick to well reputed vendors and branded batteries. A lot of user experience (not only in the vaping world) recommends the AW branded batteries. Another great option (probably better) are the Panasonic batteries. There is no good reason, ever, to skimp on batteries.
I would recommend several vendors, with the caveat that this is from a limited experience:
Super-T,
Oveready.com and
RTD