ok, I have been looking in tirerack.com, and this is what I ahev found that I am interestet in:

My top 2 options are:

Yokohama Geolandar H/TS 255/55H/R18 or

Michellin 4 x 4 XPC 255/55HR18

both have good reviews in all categories (which is important since we get evary kind of weather condition here in Boston)

I also look into:

Yokohama 265/60/R18 and
Michellin 275/55/R18

but I am not sure about this last two because I don't know if it will require modifications for my ruck or if the preformance will be affected.

In any case, tomorrow I will be calling the yokohama and michellin dealers close to my place to get info about price and avalability, but I would sill like to hear your input... thanks