I have a Freezer 13 Pro that I reviewed recently (
link), it has good cooling power and a mere two clips (for fan removal) and two screws gets it off to replace TIM. Very quick/easy.
The Freezer13 (non-pro) I haven't reviewed yet (will be later this week/weekend), but it has the same mounting setup and is $10 cheaper.
Either one sounds ideal for your testing.
The pushpins are quite solid, they take a bit more time to get in than Intels, but are stronger IMO.
Best part though is that the frame stays pushpinned into the mobo, and the heatsink screws to the frame.