Pross and cons of these? Wich Would you choose For sequential Fuel/ignition, N/A BBC engine.

I’d keep it simple and cheap with a sniper.

I have Holley HP's in my boat, and I'm just finishing up a Terminator X install in my 1987 Mustang. The Dominator would be overkill. The Terminator X would be able to do what you need, but is not marine rated. It is just a ECU in a plastic housing, where as the HP is in a metal housing and potted for the abuse of rough seas. I'd go with an HP.

Buy a holley hp, the terminators are "junky" , the dominator does a bazillion things youll never need, Smitty

I have Holley HP's in my boat for about 5 years now and they have been flawless.

What kind of problems you Have had with The Terminator?

Terminator you have to run a specific O2 sensor and harness. They feel cheap but will work for what you need.
Dominator is total over kill and it`s pretty big so fitment would be an issue.
HP`s are solid and compact.

I have a bunch of Holley sensors and stuff, brand new. I will sell em at cost .

Ive installed/ used at least 10 terminators and had NON INSTALLATION related issues with at least 3., same with regular snipers (jurys out on the sniper 2). One of the terminators would randomnly completely lose ALL of its memory on dyno, rerouted , re terminated and re-grounded everything, blah, blah, blah, made no difference. Customer borrowed a different identical ecm NIB from another guy who was further behind in his project and it had ZERO issues with same wiring, etc on the dyno simply plugging it in place of other one. He sent it back to holley who said they couldnt find a issue denying his warranty and of course they blamed the install.

One that would lose its programming completely randomnly that holley blamed on install (see other post of mine)
one that would do something with the injector drivers randomnly and hydro the engine with fuel
one that one that would go lean randomnly on my dyno after was fully tuned (injector drivers again), mighta been that 4 injcetors would fire vs 8 sometimes, a different terminator on same install didnt do it
Some people b;ame these issues on quality control during and right after covid happened, I was shocked to see a writeup that GM uses the terminator on the 1000 hp 632