Hi. I have tried using the Heineken and New Castle kegs with poor success. These guys have a big CO2 cartridge inside them and if I remember right, you have to drill the top out to be able to rig up a bike valve. After I drilled, my hole was a little jagged so I had to file it down and I forever had a nice iron taste if I put anything in. I couldn't get all of the filings out and I really question the CO2 cartridge because you can't get it out and clean it well.
I aborted that style and went with a design somewhere from the NB boards I think that used the gravity style kegs with the spigot at the bottom. This style was much better but a little more $$ to build. I used a Bells keg when I did it. The top hole fits a tiny bung and then you mod it to fit a T-joint. One side is for a bike tire valve and on the other, you insert a bent stainless dip tube for serving. This style worked a lot better for me but sealing the dip tube was really finicky. Bending it was also terrible but the system did work well. It used a full CO 2 cartridge to carb up and then 1 to serve over time.
I also tried to re- use a coors mini keg system ( plastic bottle ). That failed miserably but they have a nice weighted tygon dip tube that I still use today. I slap that onto a syringe for my DIY wine thief. I also used the tube as the dip tube for the Bells keg to save money on stainless steel tubing.
I think the cost is a little high though for the gravity keg style with all of the stainless fittings and charger where it might work out to the same price as buying one of the party keg things from NB. Check the pricing on that.