There are a few that you can use. Of course you already know about the A6 setup.
Beyond that you can get an M2 tripod which is what the original 1919 was mounted on. ORF is selling Izzy M2s for around $650. I don't know if they include the T&E or pintle. You would have to check with them. This is probably the most expensive option.
Most guys just starting out go with the MG42/MG3 AA tripod with a 1919 adapter. You can get the tripod from many different places for less than $100. There are plent of people making adapters for these. Some come with dual ammo can holders. Some with T&E units on them. Most of them run about $100-$200. What's really nice about this is that you can set them up for a sitting or standing setup. Here's a pic of Weaponeer's 16" 1919 Flamthrower on the AA mount.
Another option is a Sokolov mount that is included when you buy the 1910 Maxim parts kit. The entire kit runs just under $600 before shipping. Compare that to the M2 and you can see just how good a deal this is. We are currently running a group buy on these right now. Here's a link to some pics of the 1919 on the Sokolov mount.
You can also use the MG42 Ground Mount. Tapco has these for $500 right now. This is a hell of a deal as it include the optics. Tapco also sells the adapter for the 1919. Here's a link:
I'm using a ZB37 tripod that we got in the last group buy. I had to have an adapter made but it's a great tripod. Here's a pic of weaponeer's dual 1919 crankfired setup on his ZB37 tripod.http://www.weaponeer.net/photos/pictures/twin.jpg
I hope this gives you enough options. All of them are great. Each has it's own pros and cons. Hope that helps.