brushless losi 8b

hi guys, i have done quite a bit of searching on converting a losi buggy and was wondering what your thoughts were on this setup:
mamba monster 2200kv combo
Rc-M motor plate
6s lipos (i was looking at the flightmax 5000mah 30C lipos???)

basically what i want to know is if this is any good for bashing. i won't be racing but want something that will be able to cope with a high voltage out of the box rather than upgrading the revo

what sort of gearing would i need? i am after the longeset run time and about 40mph top speed maybe?

thanks for looking

richard