Interesting selection you've got there! I'm quite familiar with three of the blends you've picked, so I'll give you my thoughts on them.
CAIRO -- This is one of the most unique tobaccos on the market. Nothing else tastes like it, even remotely, IMHO. Lots of bright virginias, lots of REALLY exotic oriental leaf, and a noticeable amount of perique. Some say it has some kind of topping, but I remain unsure after smoking it for ten years. This blend has a lot of "high" notes with virtually no "low" ones -- imagine a car speaker with the treble set on high and the bass on low. This is kind of weird, but the flavor makes up for it. Exotic, complex, incense-like, etc. One caveat is that it's one of the last blends I'd recommend for a novice smoker. The nicotine can really sneak up on you at times, and it will bite the heck out of you if you don't smoke it slowly.
BARBARY COAST -- This is one of GLP's most popular blends. It's basically a light, American style aromatic. Lots of cube cut burley and perique here, with a heavy helping of spirits (rum, if I recall). This is fairly tasty, but I've always had a hard time getting it to burn. Not everyone has that problem, though. Just dry it out, pack it loosely and enjoy. It's not my cup of tea, but a lot of guys swear by it.
SUNDAY PICNIC -- This is a sweet, American virginia. It's fairly mild and remarkably enjoyable for something that is as....well, "bland" may be too strong a word. I would say this is "pleasant" rather than "spectacular." It's a good comfort smoke, I guess, but I prefer powerful flavors. There is a light topping applied here, but nothing distracting.
I've never tried Samovar, as I dislike McC's Engish blends.
I'm kind of surprised that those are the Pease blends you'd pick, as he really shines best with latakia mixtures, but then again if you're looking for "American" style blends I'd say that Barbary Coast is as good a place as any to start (although Jacknife Ready Rubbed would be another). Cairo is definitely NOT an American style blend, but still worth trying out.