Is it ok to put these fish together in the same tank

Tangs need a lot of open swimming room and many are not recommended in anything less than 100 hundred gallons but perhaps a kole tang would be o.k and if you want an angel then a dwarf angel is the only type you can get. The lionfish not a lot about them but i do know one thing get it LAST so the smaller less aggressive fish can establish a territory the eel i,m not sure about also do you want a reef. if so beware of the angels they sometimes nip at corals.

After you think you're fish have had time to establish a territory question reef or FOWLR?

P.S A tang would be o.k if you plan on upgrading soon but first tank specs?

A dwarf lion so that gets to about 8 and a half inches i am honestly not sure the eel forget 20 inches so that won't work. I'll get saxman on it. i'll PM him i don't know a lot about lions.

I PM'ed Saxman he should help out soon.

Actually, the lion should go into the tank FIRST, to get it established and weaned.  Lions aren't aggressive in the least, and are often the victims of bullying, but will indeed eat fish and crustaceans that will fit into their mouths.  I recommend a dwarf fuzzy as your lionfish (Dendrochirus brachypterus).  It will likely end up being  5" - 6" (TL) in captivity (figure about 75% - 80% of max wild size).

Large species angels and lions are bad juju...the angels will often nip the lions spines off and kill it.  One of the more peaceful dwarf angels would be OK tho.

As for the SFE...IME, they're fine when juvies/sub-adults, but with size and age, they become pretty aggressive and often take to eating tankmates, and I think that down the road, you'll have way more issues with the eel than the lion.  In fact, somebody on another site just had an eel (a whitemouth) eat his 7" P. volitans...

What are the dimensions of the tank?  Is it 36" x 18" x 30?

If so, a 36" tank isn't a good footprint for even the mellowest tangs, as being big swimmers, they tend to "pace", and with cabin fever comes aggression.

HTH

Perhaps a trigger saxman would that be ok with a lion there are some out there that do well in 70 gallon tanks.

If you want to keep an eel, you could go with a golden dwarf moray/GDM (Gymnothorax melatremus) which only reaches about 10" in captivity, so it's too small to swallow most fish.

A 70 gal is actually pretty small for ANY trigger, and the planktonic-feeders require more room, altho you'd arguably be on the hairy edge of too small for a blue jaw trigger (Xanthichthys auromarginatus).  However, you could go with one of the smaller filefish such as the bristletail (Acreicthys tomentosus), which has the added bennie of eating Aiptasia.  IME the bristletail is peaceful and a model citizen, but I have heard of individuals that are fin nippers.

A flame angel should be fine, as would one of the smaller squirrelfish/soldierfish species.  A great fish for larger dwarf lion setups is a trio of Odontanthias borbonius anthias (blotched anthias).  We've kept a trio in our small lion/scorp setup fo a couple of years now, and they're a great addition.

In choosing tankmates for your lionfish, the two major considerations are "size differential" (can the lion eat the other fish) and aggressive species/fin nippers.  Also consider that long/cigar-shaped fish are easier to swallow than "taller" fish.

HTH

O.k try this coral beauty angel tomato clown eight-line fairy wrasse and perhaps a sargassum fish if you are going for a FOWLR. All hardy fish and should be fine together.

I don't think so.

Lion is alot of work to tell you the truth. Sacrifice one to gain many I say. :)