S30 or smaller co2 bulbs?

[panderson]

I'm looking to start brewing beer again after lots of years, looking at getting a kingkeg as used to use these. Is it best to go for the s30 adapter or the pin one so can use smaller co2 bulbs? Haven't got any homebrew shops nearby, so not sure where/how to get the bigger cylinders then get them refilled.

 

[Its 6pm somewhere]

Would it be worth considering a 20l oxibar keg instead? You can use the small co2 bulbs with a ball lock connection or you could use a sodastream set up, easy to get refills.