I like the idea of buying a bike and then re-selling when the time comes to leave. I'd try to set it up with a more well-known member on this board, and if it comes down to it leave the bike with them and ask them to sell it for you... I'd do that for ya if I was on the left coast still.
Cali's beautiful man... I'd get on the PCH and ride the whole thing. Start down in San Diego, head north and stop wherever you want.. Definitely hit the Redwood National Forest, that's a damn beautiful place. I've never been as far north as San Francisco (OK, so I've been up through Utah... But not in California), but riding through that hilly terrain would be a trip to say the least! I'd shy away from Los Angeles personally.. It's really congested ALL the time, and there isn't a whole lot to see (other than the Sunset strip.. bleh). You've gotta hit up the beaches, and I think riding along the PCH would be ideal for that!! Big Bear Mountain, Lake Tahoe, the town of Baker (the worlds largest thermometer at Bun Boy, and the Belgian Waffles there are killer!! And the restaurant The Mad Greek, best freakin shakes EVER!) which could very easily be on your way to Vegas, if you want to pass through Pahrump. Plus, if you get a dual sport and wanna venture off-road, roll through Baker and head out to Dumont Dunes. The off-road season kicks off on Halloween, so if you go out before that you'll pretty much have the dunes to yourself (It'll be sweaty-balls hot though)! If you wanna ride on the beaches, hit up Pismo Dunes, and of course... If you start out in San Diego, head another hour south and hit Glamis!! Best dunes short of the Sahara!
(No, I don't really know that for a fact, but they're badass)
If you like theme parks, hit up Disneyland. If you like shit-your-pants rollercoasters, hit up Knott's Berry Farm. If you want a water park, go to Raging Waters!
Head North to San Fran, then East to Las Vegas (it's back south-east from there, but whatever). Vegas would be awesome on a bike! Hit up Pahrump if you want some legal fireworks and prostitution... I'm warning you now about Vegas though. Either go during the winter (our winter that is), or risk MASSIVE traffic jams during the summer (at night at least.. Everyone in Vegas is nocturnal man, the streets are barren during the day).
I don't know what to suggest to you as far as best time of year... No matter when you come here, you'll have good enough weather that you can ride whenever. Winter's in Cali get pretty cold (like down into the 40's at night), but the daytime highs are still 60-70*. Summer... Well, it's more like what you're used to. Highs flirting with 100 inland, and down south towards Mexico and getting closer to Death Valley and Vegas, you'll be seeing 110-120*.
I'd personally try to come in the fall... It's gorgeous. I was just back out in Cali for my cousins wedding in September, and we were at 95-100* all week long, and the lows never got below 70... Beutiful riding weather, and the days are still plenty long! Anything later than October and the rain's more frequent (still pretty sparce..), winds tend to pick up a bit (mountain riding should be fun.. haha), and your days are gonna be shortened quite a bit.
Alright, I know I'm forgetting some stuff... But I'll tell you some other cool stuff as I remember.
One extra bit of advice; Stay on the left coast. The more Eastern you get, the less hilly (past the Rockies I mean), more flat, open plains... And hill billy. California, Nevada, Utah (which is GORGEOUS!), Oregon, Texas, Arizona, New Mexico... That's about the extent you'll wanna see. Stuff starts to get more dreary weather-wise beyond that.
