personally, i wouldnt buy any of them. the traxxas is too expensive for what you get (you can get one of several 4wd's for the price or one of it's competitors for a lot less), the mini 8ight is too big for the components in my opinion and the rc18b2 is belt drive which isnt known for being friendly with dirt.

if you could push your budget about $70 for everything, i'd get this buggy http://www3.towerhobbies.com/cgi-bin...&I=LXAPPP&P=SM this battery http://www3.towerhobbies.com/cgi-bin...?&I=LXUUE5&P=0 and this charger http://www.hobbypartz.com/73p-ac680-accharger.html

i have the little brother to that charger and have had no issues.

if you cant swing the extra money, i'd get an rc10b4.

if i had to pick from the 3 you listed, i'd take the losi and look into a 540 conversion.