Wassup Ross,
I spoke with Kevan from United Composites last week; he is their primary blank builder. He had just finished building me 6 10'6" butt joint blanks for GT shore rods. We spoke for a few minutes about their line of Sidewinder Blanks. I asked him if they were designed as Tuna/GT combo rod like most of what is readily available from some blank builders now (Temple Reef, Black Hole, Race Point, Phenix, etc...) He told me that they are designed with only GT in mind and do not have the parabolic action of a tuna blank. That was a good thing to hear. As Kevan told me: "They're really F***in stiff man!"
As for availability with most UC blanks, you may have to wait a while to get one once you put it on order. Does UC have another factory in AUS as well as here in the USA? For their factory in California, it has taken me anywhere from 3-6 months to get a special order blank once i have placed the order. Kevan has just told me that they have hired some additional staff, and that blank production time should be becoming quicker. As it is now, he said to expect a 6-8 week wait period to get a Sidewinder Blank on special order. They are backed up on production enough now, that they are building most of their blanks to order from the customer, and not building to fill stock in their factory.
If you can call around to enough shops you just may get lucky and find one or two Sidewinders available. Most likely you'll have to place an order and wait, as Kevan said that not many have come out of the factory yet.
I'm looking to get a few of these in the near future also. Very interested in trying out the PE8 and PE10 blanks, and will report after they have gone through a few cycles of the GT rodeo on Oahu.