Ship, have you considered Nitto NT05s?
235/40ZR18 XL 95W B
265/35ZR18 XL 97W B
~840 shipped (depends on location)from discounttiredirect (for some reason Tirerack doesn't carry these).
There's a pretty good discussion on this tire (and other options) in this
wheel thread. From what I've read, the Nittos would be an upgrade from the Contis for the track and are more equivalent to the Star Specs. Looks like they have the right fitment for 10 mm wider on the stock wheels too.
If a good amount of the wear/use expected in on the track, and you drive the truck in the cold/wet anyway, I'd lean towards tires that have a compound and tread pattern more equipped to deal with the stresses of track driving (and hold up under those conditions) and which will give better performance on the track as well. The only downside to a tire like the NT05 or Star Spec is that they are absolutely not to be used in the cold/wet (by cold I mean 40 degrees or under).
The Ventus and Vredstein have a large amount of tread squirm until they're decently worn (lots of review on these.) Looking at the tread pattern on the Firehawk, it looks designed for wet traction more than track work (it has tiny little tread blocks) and is a performance all-season tire, not something that is probably well suited to track work (like an Extreme Summer Performance Tire). UHP has tiny tread blocks as well, soft sidewalls, and poor cornering grip (from reviews).
Some tires may be cheaper initially, but if they end up chunking or melting (and getting greasy) on the track, then that is going to both cut down on the fun and also end up costing as well. It's kind of about using the right tool for the job IMO--but that's just my point of view, YMMD.