Some thoughts on Quake...
First, PM me regarding when you want to hit quake. I may be able to ditch work and connect with you. Knowledge of the various lines and the handful of hazards from someone who knows it well is a wise move before hitting solo laps.
If you are comfortable soloing in Class IV-V whitewater you do not know, then you don't need my advice... You will see it when you scout. That said, a playboat is a piss-poor idea for this run. Anything that may help you to pin under/in the sharp, shallow slide debris or assist in getting you upside down in that nasty business at speed should be avoided. There is no call for that type of craft on Quake, in my opinion. Sure, it can be done and done well... But why handicap yourself? If you pin alone, you are done and the shore "lines" are the epitome, if not the definition, of blast rock mank. No one is going to get anywhere near you in time and it is gonna be a ugly, desperate ordeal, if not a horrific and untimely passing. Even at low flows, the speed of the water is tremendous and the rock is very, very fresh. 2 of the 3 boaters I know that have swam it name it as one of the worst and thee worst swim of their lives, respectively. These guys are solid and well-travelled class V boaters with plenty of epic wet exits under their belts.
The same logic goes for Henrys Fork. The sheer height of the falls means a spine issue is well within the realm of possibility, and again, no one will get to your aid in a reasonable time frame. As stated above, if all goes well, it is an enormous plop and drop that many a green boater has styled.
For the record, I love to solo Quake and would venture to say I have more runs on it than anyone (Well over 100 laps, majority solo). I am a local and it is a place I go often to check my pulse. I just felt the need to point out that neither of these are casual solo endeavours, even if your skill level is high. And the risk/reward factor should be seriously considered.
Drop me that PM and let's see what we can do. I swear I am more fun than the geezer slathered in old folk cream that scrawled the paragraphs above and I am so god-damned handsome and chiseled that hitching the shuttle is a lark. (Read: 29 laps = vertical mile)