I encourage you to buy a popular 27-30 starter boat. Your experiences with this boat over 3-4 years will prepare you to sensibly pick the bigger, long-term cruiser. I think the chance that you can buy a first boat and have it turn out to be a boat you want to stay with in the futre, let alone sail distances, is very low. You'd be shooting in the dark.
I personally think 30' is the sweet spot, comfortable enough for a couple, but easy to handle. Some advice;
1. buy a boat that has been used as you intend to use it - cruised by a couple I guess. Look for self tailing, oversize winches, roller furling, all lines led to the cockpit. Your wife shouldn't need to do anything, other than watch, unless she wants to...
2. Buy a well-equipped, well maintained boat. Such boats are easiest to sell and are overall cheaper than any "good deals", below market price examples. Nothing is more expensive overall than fixing up someone else's neglected boat. This is especailly important for the first time buyer, as you can't imagine how much there'll be to repair or replace, or how expensive it'll all be.
3. Quality boats would include C&C 30 I, Tartan 30, Catalina 30, Sabre 30, Parson 303, and my favorite in this size Cal 28 II. Take a look at one http://yachtworld.com/core/listing/b...101&searchtype