welcome to IIS frosty
Take some time have a good search round the site ,theres lots of great info
here on choosing scopes .
On the etx 90 , I honestly havn't looked through one , the 125 I have and
it seemed fine , certainly portable if thats important .
A lot is what you want from a scope and the little compromises you take on board along the way, and 8" dob will show you a lot more than a 90mm mak but its not as compact as those small scopes.
good luck with your choice and enjoy your time here friend