I've kept them together in the past, they will get along, but the tank is too small for 4 to 5 of each.
First to be successful you should seperate the habitat of the jawfish and eels, the eels will make their burrows in sand, but the jawfish need some sort of roof. The best way to give them this is burry flat pieces of rock about 1/2 inch under the surface of the sand. Also the jawfish do better with rubble to build the entrance and tunnel to the burrow, both of these things will irritate the eels and if the tail scales of the eels get damaged by the rocks or rubble hitting the tail it will kill them, and the bad thing about that is the eels never leave the burrow so you wont even know the damage has been done.
What I would do is set up the tank, give the eels at least 2/3rds of the tank just sand, and the other 1/3rd with rubble and burried rock for the jawfish. Then get the eels first and make sure they are feeding and doing well, Namxas is correct in the fact that they wont feed if there is a lot of distractions until they are settled. In the ocean the eels have at least one sq ft per burrow, so in your tank 3 would be the max I would try, and 2 would be better for the space you have. After they are feeding and doing well I would add a pr of jawfish and watch them for a week or more, making sure the jawfish build their burrows on the areas you want them to. My eels were pretty easy to keep, I collected them myself and as long as the food was the correct size and was moving around the bottom of the tank they ate it, including dry foods. The size needs to be small but not tiny, cyclopeese and baby brine were perfect for them.
One last thing, both species will jump out of the tank at night, even when they have an established burrow, so keep the tank covered at all times, but especially at night.