What ever you do, DON'T put a 16 mast on a 14. You will not be very happy with the results. The 16 mast itself is much heavier and the 16 sail is much larger than the 14. The hulls just can't take the extra weight. It is hard enough keeping the leeward hull out of the water as is. I have also heard about people wanting to put 16 beams on a 14. Again, they don't have the buoyancy and the geometry would be all off.
I'm in the 175-185lbs range and I don't have a problem on my 14. The Turbo makes it easier to tack, but it really doesn't add that much more to the boat. The cheapest way to convertyour boat is to get some good, used 16 rigging and cut it down to fit. Jibs come up every now and then on eBay as do the blocks. I got a great deal at Whirlwind sails last year when I ordered a bunch of jibs, so you might want to try there if you want an aftermarket. Of course, Hobie jibs are well made and class legal.