Nice choice on going for a BP/W setup right away. These things are quite uniform, practically to the point of being interchangeable, so the various makes/models are probably all just fine. Not familiar with the Mares bladder, the only thing I would flag is to get one that's not too small, and not too big. There's absolutely no need to get a wing over 40 pounds, no matter what anyone says -- especially if they're advocating it to future-proof should you decide to go for double tanks later! My OMS wing is 32 lbs and it works great for a single tank in cold water, either wet or dry. I have used it in warm water as well and it was fine. If I ever start diving warm water a lot, I'll probably pick up a smaller one, 15-20 lbs or so.
If you're looking for a good, cheap 7mm wetsuit, you will not find a better one for $225 than the Deep6 7mm. I got the 3mm a while back for warm diving, and like it so much that I almost bought a 7mm as well, even though I already had an 8mm Aqualung wetsuit and a drysuit being manufactured at the time. I'm glad I didn't do that since I'm so happy with my drysuit, but I really wish I had known about the D6 wetsuit when I bought my Aqualung for more money than the D6 would have been (even before the recent discount). Honestly I've never heard a single negative comment/review on these suits.
The only thing I would suggest is that if you are in between sizes like I am, you call in to ask for advice. In my case I'm at the high end of some of the M measurements, low end of some of the L ones. I went for the Large, which ended up being way too big for me. Gave that one to a buddy of mine, ordered a size M, and it fits beautifully. I couldn't be happier.
I can and did dive the Monterey with a thick wetsuit year round for shallow dives with no issues. As I got my skills dialed in, purchased steel 100 cubic foot tanks, started diving on nitrox instead of air, and generally doing deeper and longer dives, the cold began to be the limiting factor. It got to the point where we would often turn dives with plenty of gas remaining and plenty of NDL time, just due to the cold. So I started researching drysuits. If you take a look at the "Exposure gear" forum, you'll find many glowing reviews for SeaSkin brand, who make solid suits for half (half!) the price of many popular brands. Now that it's here and I have dived it just a few times, I don't think I'll be diving wet in cold water any time soon.
I haven't dived in Southern California yet so cannot speak from experience about temp/gear differences between here and there. Consensus seems to be that it is a bit cooler in the water in Monterey (like 5F), and a lot cooler on the surface (like 15F). So I could imagine some folks would prefer two different suits for the two different areas, but probably most people who dive dry in Monterey would be happy dry in San Diego as well, and vice versa for diving wet. Again, not speaking from experience here, just some guesswork. By the way, one of the most popular drysuit manufacturers is DUI and they are based in San Diego. Their stuff is far from the cheapest, but many consider it to be the best. If I lived in San Diego, I'd make it a point to visit them in person before moving up to the Bay.
Best of luck, and welcome to the board and to scuba diving. I hope you find it to be as much fun and as rewarding as I do