The Stealth fan gives 53CFM, and the Thermoflow gives a max of 92CFM.
As for the Panaflo's... I've found some!!! Seems this is the only UK distributor: www.DorothyBradbury.co.uk - Silent & Industrial Fans - Panasonic Industrial (NMB-MAT, Panaflo) - 40mm to 172mm
And so that you don't have to click the link, here's a screen of the one I'd probably get (highest CFM of the lot, so it's a no-brainer, right?
As for paste, I was thinking about Arctic Silver if I were going to get some, and you've made my mind up for me.