What would you folks say the best strategy is for targeting 2nd tier and potentially boutique consulting firms? I don't necessarily want to work in an MBB firm, but a place like Booz or Accenture, Monitor, PwC, or potentially even a smaller boutique with room to grow would be stellar. Would I still need an MBA form Insead/LBS/Columbia?

These are very different firms. On my profile page I link to an post about how to find the best schools using LinkedIn. Try that. Certainly Booz and Monitor hire from schools at the level you suggest.

Fully agreed with Duncan. Each of these firms will recruit either based on field expertise or based on location. Booz seems to nab a lot of folk from Maryland Smith and Georgetown, which is not a surprise based on its location. PwC is probably going to pick up a lot of people from quant heavy schools like Booth.

I suggest really narrowing down the firms you want to work in and then do some research on where these firms recruit from. In general the Insead/LBS/Columbia tier of schools is probably the safest bet.

So what you are saying is that I have to shell out the big bucks and then take the GMAT, even if I don't want to work in MBB.

The GMAT is very well suited for consulting work so, other things being equal, consulting firms will tend towards schools with strong GMAT scores. Tuition really is the best investment you can ever make,