I have zero experience with spey rods and spey type casting, but do a lot of surf fishing for striped bass with 1/0-3/0 flies with both full length lines and shooting heads. Hopefully, some folks with more GL experience will chime in, but here are some things to consider-
"Switch rods" are designed to be able to do both single hand and spey type casting. They tend to be a little longer than single handers and shorter than speys, and have a a small fighting butt style grip below the reel for two handed casting. Trying to single hand cast a spey will be difficult and tiring. Whether switch rods are a good compromise or represent the worst of both worlds for what you're looking to do is a debate I'll leave to others with more experience.
As far as spey rods go, be aware that there are a lot of different styles of rods and line weights/tapers depending on the application, and matching up lines to rod is critical, depending on the application, as well as matching the rod. For more info, look to Speypages
as a great resource. There are also a lot of "spey claves" held in various spots, and attending one would be a great way to get your hands on a lot of rods, lines, and get some help with the casting and technical help to get pointed in the right direction with the right gear for what you're looking to do if you want to explore the spey/switch thing. Hopefully someone here will chime in that knows more about it.
As far as shooting heads with "regular" fly rods, I think a 9 or 10 foot long 9 weight might be a good choice based on NE Surf--again differ to local experts for GL, but I would think a 10 wt would be a little overkill, except for chinook. An 8 wt might also work, but you might find it a little undergunned throwing 1/0 flies, especially if you've got wind to deal with. A 9 wt would be still light enough to blind cast all day, have enough ooomph to throw bigger and weighted flies and be enough stick to turn big fish, including the occasional 'nook.
I typically do go up 1 or 2 line weights in grains (2 most typically) with shooting heads. This can be tricky though because shooting heads are often sold factoring this in. For example Rio sells shooting heads "for ____ weight rods" that are designed to be heavier and for the "___weight rod" as opposed to equalling the grain weight of ___weight regular fly lines. Shooting lines can be sold as "integrated lines" (heads fused to running line). These are the easiest to use, and don't hinge as much as separate heads + running lines are prone to do. They're not as flexible of course because you can't change heads for different densities if you need to cover a lot of different water depths as you could with a wallet of different head and loop to loop connections with your running line. For running line I use Air Flow Ridge Running Line (30 lb intermediate). There’s other stuff out here, but it seems to tangle less, and is easier in cold water when wading since it won’t be apt to cut fingers as some of the smaller diameter “distance” stuff. I also use a stripping basket (rubber maid dishpan + bungee cords) to help keep line under control, and it adds a lot of distance compared to trying to shoot running line off the water (especially intermediate).
Again, differ to local experts, just wanted to give a general idea of things to investigate.
Hope this helps