I love my 40 breeder but for a true first tank I will always recommend 75g, it is a perfect middle size. While bigger is better something like 90percent of people last a year or less in this hobby and the equipment, tank, lights, rock, sand and various other bits you need for a 75g will only run about a grand give or take to get you started new. You wont be out a ton of money if you decide it is not for you either, prices tend to jump past 75g as well.
If you go craigslist you can get a heck of a deal but PLEASE take an experienced reef keeper with you! I would pay $800 for a used system without livestock if it was in pristine condition but $200 for the same system with hair algea, aiptasia, ich, red bugs or any other of a myriad other plagues I would pass on. Yes the problems can be fixed but for your first tank you will get very frustrated with the money spent on fixing it and/or the 6+ months it could take in time and constant attention.
There litterally are thousands of reef keepers in your area, do a google search for local clubs, there are bound to be people willing to help you find the tank for you. Reef keepers tend to be a close group with very few bad apples. When I started this hobby I did it on the spur of the moment and just happened across my local clubs flyer at the local fish stores bullitin board and without them I wouldn't have lasted 6 months...