dunno about which frame to get, it depends on a whole bunch of factors; riding style, personal aesthetics, und so weiter...
as for pitch, what you're talking about is actually width (chain pitch is the distance between rollers, see here
http://www.sheldonbrown.com/gloss_p.html#pitch for more info). 1/8" chains are used on bmx bikes and lots of true track bikes, while 3/32" is used on most road bikes.
unless you're an absolute monster you should be fine with 3/32" for road riding.