check on craigslist, get a used mountain bike, aluminum frame, no more than $500 (haggle! and if the price isn’t right, walk away, there’s always deals). look for a giant, specialized, trek, gt… balance/access… look for shimano deore, lx or xt drive trains or sram x7.

get a bike with a rigid frame and a front suspension fork. you probably wont get a great fork for the money, but should be ok from the past 3 years. look for manitou seven, scarab or black or rockshox reba (not likely).

with a mountain bike’s design, you can put $10 road tires on it and go cruising through the city just fine. no need for “city” bikes and far more versatile than just getting a standard roadie. not to mention, the sitting and pedalling positions are more tip over resistant.

make sure you get a bike that is your size. don’t buy too big and shove the seat down to accomodate, don’t buy too small with the seat pulled too high. some bike frames have a sloping top tube design that may make the seat look too high, but it’s not. the lower tubing makes for crotch friendliness.

check out rscycle.com, pricepoint.com, performancebike.com for price comparisons. check mtbr.com for their forums. of the san diego stores, performance, bicycle warehouse, adams avenue bicycle are ok. but go armed with info and don’t let the sales people bully you.

the san diego bike swap is in october. some good deals can be had there. $1000 can build you a very nice bike with a mix of sale, used and overstock/older stock parts. might be cheaper now with the shitty economy and people dumping their toys. i’m getting sale and coupon emails constantly these days.

oh, if you can’t adjust/fix shifters, you may consider a single speed. gear it for your needs (hills or flat?) and just pedal.