It's not unexpected for shop employees to have opinions as varied as those in this forum. I guarantee that if you return to the same shop and speak with a different person, you'll get a different answer again.

One suggestion? Ask to speak to someone who rode their bike to work - or look for someone with a grey beard...

The problem with helping new people is that you can't always trust their analysis of the situation. For instance "heavy traffic", or "bad roads" or whatever... Your own opinion of traffic/roads/etc will change considerably within first few months of commuting regularly, and continue to change the more you ride.

Anyway......

My feeling is that step 1 should be to decide what type of handlebars you think you would prefer, and what your budget is.

Both a hybrid (trek fx) and cyclocross (portland/tricross) will both do the job - as will about fifty other new models, and hundreds of used ones.

Choosing your handlebars will cut the field in half and make the decision a little easier.