I would Definitely get the 150 then and have foam added to the luff for proper sail shape through a greater range.
I would also keep the inter stay and get a storm stay sail and make it removable...there for curing your feed through problum as you can stow it using a spreader horn and a dedicated "D" ring on deck or along the toe rail somewhere.
The reason for this is two fold...Most 150's are not going to be designed for winds greater then 30 and secondly... even a furled up sail risks a fruler line parting and that will lead to unpleasantness to say the least when things pipe up... if one were to get spooled out on you in gale conditions think broach or worse here...so that interstay with a hank on can come in real handy caught out in a blow...or for that matter going out in one on purpose...
...welcome to the club.
Below is what I'm talking about on the removable stay sail anchor.
PS: I second the versatility of a high clew 135..my boat came from the Bay area and my 135 is built brick house stout...we had it out in 47 Knt gusts a couple weeks ago with just a 100 Square foot patch of it up I did not worry about the sail itself at all ...it was the furller line that made me a little nervous...my new removable inter stay set up with hank on storm stay sail like I just described will be just the ticket in thoes conditions...but my 135 is going to be built way to heavy for light airs and thats why I'm suggesting the lighter 150 with foam for you.