I suggest that you read the essay entitled “Double Degree Dilemma” closer to the top of this forum, that basically covers the different paths for study of music.
I sounds like freestanding conservatories may not work for you if you want “college-y”, unless they are integrated with a college campus with a BM program.
First choose between a BM or BA, or double degree:
A BM program would provide 2/3-3/4 classes in music and usually involves auditions. Since you want a small school (which would leave out larger university schools of music) you might want to look first at liberal arts colleges that have a conservatory on campus.
Examples of liberal arts colleges with BM programs (Is there a reason you want West Coast only? )would be Oberlin (I know that Oberlin would have jazz guitar), Lawrence, Bard(not sure about Bard; and they require a double degree for conservatory students). Hartt at U. of Hartford used to have good guitar. I haven’t checked recently.
As I wrote before, there are options on the West Coast as well (see previous post).
In all of these schools, check out the jazz program for guitar.
Your other option is to apply to a liberal arts college for a BA (usually 1/4-1/3 classes in music, and no audition; you submit a music supplement with recording, music resume and music letters of recommendation). Often colleges will find you a teacher, if they don’t have one (Middlebury and Williams offered this, as examples) and you can do lessons and extracurricular performance. You can also do gigs outside of school. Again, look at my previous post. Lewis and Clark and the Claremont Consortium (Pomona, Pitzer) might be possibilities
I will mention that Oberlin has a “low wall” between conservatory and college and have enhanced the BA in Musical Studies to include more opportunities in the Con. That said, it sounds like you would prefer the conservatory.
There are also double degree programs. For example, Tufts/NEC. But I will say I also love the Tufts music program for BA students and that would be true at many schools.
You have some research to do. First look at liberal arts colleges with BM programs. Then look at liberal arts colleges with BA programs. Make sure jazz guitar is a major. Don’t be afraid to email or call music departments to ask. Particularly about teachers, if that info is not available.
You may find some surprises. For instance, tiny Bennington College had excellent guitar. Not sure if that is still true, but it is an example of a surprise you might find.