Cost aside - i would buy one of those before a handheld (from B3 or otherwise) CP filler. Beerguns i have no experience with, but in general i dont like the idea of them and much prefer the notion of filling undr pressure. They may be perfect for all i know - but if like me, you prefer the idea of a CP filler, then this unit is one of the best looking homebrewer grade fillers i have seen.
Apart from that - i can recommend units available that fill PET bottles. They can be font or fridge mounted and used entirely with one hand.
They are based on Pegas bottle fillers and youcan look at the original units here
http://beerinnovations.com/beerequipment/PET
Choose the "manual bottle filler" link and look around the description, images and video.
I have a generic rip off version of that filler and it works a treat. Here are some links to a video i took of filling a 330ml bottle with it. Sorry the vids are sideways, couldnt work out how to rotate them. I bought my unit from KegKing in australia http://www.kegking.com.au/ where for some reason you cant see the product in the online store, but it does appear in the pricelist document. Occasionally i see the same things listed on e-bay.
Inserting the bottle and purging with CO2
Starting the fill
Finishing the fill and removing the bottle
Capped and filled bottle
Hope that gives you another option.
Cheers
TB
