Chris............I think the PS design that will best work for you must be tailored to your specific bike and basic profile. I suspect that numerous small HP bikes choose the wrong fairing because the records indicate they go slower than UN-faired. I shall find out with my own adaptation of an RS125 fairing to my TRIUMPH Cub to run at the BUB.
On the high-speed end of things.......Two years ago Mr. Warner (311-MPH) complained about a very light front-end at high-speed which may have been caused by too much upward air-pressure combined with vacuum-drag at the top.
The long-tail design may be safer at high-speed, but I think it also leads to overall faster speeds without considering the tire-safety aspect and the limitations on design at the front.
I run a relatively low power Bike in APS/G 250. I made a Fairing as per SCTA APS Rules myself. I made the Front Fairing as wide as my shoulders and and shaped so that it would direct the majority of the Air around the sides and not over me. I also tried to get my feet forward so that the sides of the Rear Tail section were as long as possible. I found that it did make a difference. The power was pretty much the same, geared for a slightly higher speed.
In 2010 in M/G 250 once I got to around 110 mph and I was in full tuck, it would slowly wind out to a top speed of 119mph. On the first Timed Track run this year, I got up to a speed that was relatively stable (had a crosswind), I was in 4th at around 110mph, I changed into 5th and opened the throttle and the Bike accelerated, (it became a bit too skatey as I was also dialing in my new suspension) so I eased off a little to a stable speed, then went through the Timed Mile averaging 113.751 mph. Had engine dramas after that so did not get a flat outrun.
Next year I am going to run the Bike unchanged, so I should know a bit more then.
Pete