Whoever said a 16 is too much boat for you should go jump in a lake.
OK, I sail on Lasers and other monohulls (up to 34' keelboats) with the UW-Madison Hoofers sailing club. I also own a Hobie Getaway. I have owned Hobie 17's and have sailed Hobie 16s. I'm 5-9 and 200 pounds, also "fairly" athletic with mountain biking, etc. Oh, and I'm almost 64 years old. So using me for a basis of comparison:
I feel like a Laser is tiny. I'm not comfortable on them, but sail them sometimes, if I don't have any crew to go with me (the club requires 2 people on the larger boats). I'm fully comfortable with their 420's (14' sloop) and Interlake Sailboats (18' sloop which can carry 6 people) but the club requires 2 people on board to sail them. These boats are fun, in their way, but much, much slower than any catamaran.
They are dryer, though, so the sailing season in Wisconsin is longer with them.
I prefer my Hobie. The Getaway is about the same size, although heavier and slower, than the 16. I'm fully comfortable sailing it solo. I would be fully comfortable on a Hobie 16 or 17 solo also (the 17 is actually a solo racing boat. It's faster than the 16 in high winds, slower in low winds, doesn't capsize as easily as a 16, but is pretty uncommon in good shape.)
I am extending my Hobie sailing season-I just bought a drysuit. Found one designed for sailing at wetsuitoutlet.com in the UK, cost about $250 with liner, shipped from England. My early season sailing will be solo, because my wife says if it's too chilly to sail in a swimsuit, it's a good day for tea and a good book.
I have the Getaway because I have kids and grandkids, and it's not unusual to have 6 people on my boat. That's too much for a 16, and way too much for a 17. I think it's too much for a 18, but I have no experience with the 18s.
So, if I were you, my first choice would be a Hobie 17, if you can find one in very good shape. 2nd choice, a Hobie 16. Others would reverse that order. For solo or 2 people sailing, the Hobie Wave is, I hear a good choice (I have no experience with them). There are nice monohulls out there; I considered a Hunter 22 before I bought my Getaway, and the Melges Scows are fun, fast boats. But there's just something about catamarans that float my boat.
But to say a 16 is too much for you? Ridiculous.
(Edit. Just found this on eBay. Price seems great for such a new boat, and it looks like it fits the bill! I'd be tempted if I wanted a smaller capacity boat.)
http://www.ebay.com/itm/NACRA-Catamaran ... kA&vxp=mtr(2nd edit, here's a 16!)
http://www.ebay.com/itm/Hobie-Cat-16-sa ... 2475743409