Look at using less extend, bootstrap is still a great boilerplate. You can still take only the less files you want from it. You'd want normalize.less and mixins.less from the bootstrap project.
You can use extend to get whatever else you want out of bootstrap.
p {
&:extend(.clearfix all);
}
img {
&:extend(.img-responsive);
}
or even
p {
.clearfix;
}
If your worried about namespacing collisions you can try your hand at some global search and replaces. If you need that, I can try to help you with it. I wrote something a while back.
Of course you need the bootstrap project source for this - go here and click Download Zip - https://github.com/twbs/bootstrap