I may be trading WAY up for a 1919A4. So far, I know nothing about it other than what it is and it has a tripod and a T&E. Are there mfgs to avoid. things to look for? I'm waiting on pics and info at this time. I'm just a lowly FO and never had crew served weapons in a training environment but I have some good field experience with M2s. Are they internally similar/break down similarly? Do they have to be timed and head spaced?

Manufacturers to avoid.  I'm going to say anything home built?  I trust mine but not sure I would trust just anyones home build.

Make sure the rivets are all tight.  An older build will have some weld on the trunnion to the side plate.  Newer builds it was not required.  The trunnion is a spot that can wear thin from running links.  The groove for the backplate can also get beat up on an improperly hardened receiver.

IMHO a non Israeli kit is not worth a premium even though folks tend to charge one.

You can get caliber conversion kits. 30.06, 8mm, 7.62x51, 7.62x54r, 7.62x39 just to name a few.

A 7.62x51 bolt will work with 30.06.  A 30.06 bolt will not work properly with 7.62x51.

They are vaguely similar to the M2 internally but a touch simpler.  They do require headspace and timing if it's a FA.  If it's a semi it just requires head-spacing. If it's an Israeli barrel and barrel lock there is a simple mod you can do to make head-spacing much simpler so you only need two hands rather than three.

Most importantly.  Treat a removed bolt like a live firearm!  The driving spring is very dangerous.  Over on the M1919A4 boards a member was hospitalized from a driving spring accident.  It went through his eye and was mere millimeters from penetrating into his brain cavity.

Top covers are still cheap enough to have a spare or two for the rare OOB explosion.  Belts are tougher to load but softer on your trunnion. They also make stainless steel trunnion protectors for running links.  If you run links be aware there are 30.06 and 7.62 links.

Ok sweet, apparently it was built by KMP from an Israeli parts kit and it's a Saginaw Steering division gun.

KMP is the go to for 1919 stuff.  I still have the pen I got when I bought their semi-auto setup for my build.  Dang that was almost 20 years ago!!

As was said, kmp is good to go.  Make sure you heads pace the gun and have fun.  The 1919a4 forum is a great place for knowledge as well.

make sure it has all its "9"s

If you end up buying a kit have John Mcquire do your build.  He did Israel kit for me over 20 years ago.

Make sure it works with links,  belts are not practical unless you have a belt loader. Some of the conversions are not worth the trouble.  They are fine when there was cheap surplus but with most commie calibers at 60 cents or more a round they have less value.

I'm also looking into getting one myself, I know nothing about them. I know I want one in 308 with a tripod.

I see some for sale from ice house mfg, and jnc manufacturing. Not sure if those are good vendors to purchase a complete unit from.

I also like the look of the spade grips. If I were to have one built I may ask if they'd be willing to install a spade grip as well.

What's a good vendor to get these things from?

Avoid ice house.

Ravenna Arsenal/Columbus Ordnance as well as Guns, Ammo, Silencers (GAS) LLC are two spectacular builders of 1919s.

John Mcguire is also very well known and highly respected for his work.

Someone was looking at buying an ice house 1919 and I told them to call Chris at Columbus Ordnance. He ended up saving thousands and getting a nicer gun.

Looks like they are out of stock. May have to give them a call or find a parts kit for them to build.