Hi Clint, I know I'm late to the party but my 2 cents on the 5 litre kegs.
I like a variety of beers available to drink and don't want to drink 40 pints of something before
I move to the next brew. I used to bottle everything in 500ml bottles and used to hate bottling day with all the sterilising, etc. I brew in 20 litre batches so 40 bottles was a pain. I then decided to bottle 5 - 10 litres per batch in 1 litre plastic bottles which speeded things up a bit.
I then splashed out on a 5 litre keg with all the gubbins from Dark Farm just to see how I managed with kegging. I didn't want to go the full cornie route as I think they're a bit unsightly in the house unless you have a bar or fridge.
The kegs from Dark Farm are solid and are a good dependable bit of kit - I now have 4 and 2 taps!! They don't look out of place in the kitchen and the new black ones look pretty cool. I also have a cheaper keg and tap bought off Amazon and there is a big difference in quality but you get what you pay for, I suppose. I find that the 5 litre kegs are the perfect size for me whereas the 10 litre ones would be too big. I prime the beer as normal and find that I use about 1 CO2 bulb to dispense a 5 litre keg - obviously it depends on how carbonated you like your beer.
I notice that Dark Farm have also recently changed the spears and disconnects with their taps so these 'might' be compatible with cornies if you want to upgrade in the future. You could email Gareth the owner to discuss your needs and see what he recommends - he is really helpful.