what motor do you recomend?

thanks guys for all of the info. the body is in perfect shape no rust at all. and the best part is i picked it up fo 1500 bucks. is looks like a new car. the slant six im not sure what kind it is and im not sure about the tranny either but it is a auto and the way to change the gears is you put the buttons on the dash left of the steering wheel. im a newbie. what should i look to spend on a mild 360 and how many miles should i expect out of it? :)