Don't own a Parker myself, but I've been told they are a very fast & accurate crossbow.
I shoot Excalibur and use carbons with it. They shoot well, and seem to be either straight or broken
(and they are hard to break!)
I've found Wasp JakHammers to be very accurate, but have had problems with them opening in flight out of my Exocet when shooting them at 310 fps. Out of the old Vixen at 260 fps - no problems at all.
I've found the G-5 Outdoors "Montec" to be an exceptionally accurate fixed blade, and the SlickTrick a good relaceable blade fixed blade, with the Montec having a slight edge on accuracy.