Hi & Welcome to the forum El Bisho,
Sounds like you've got a big job ahead of you but it's an investment of your recreational time at home so yes, you've got to buy quality and ensure it's done right the first time.
Theres quite a few big named Gas grills that make the built in grills such as Beefeater and Lifestyle BBQs...Now if I was to build my own gas grill kitchen, and providing I knew I was going to stay in that house for a fairly long time, I'd treat the outdoor area the same as an indoor renovation and buy the best that I could.
This is what I'd choose as my weapon of choice...it ain't cheap but if you look and compare to anything on the Market to what this big boy has got.....you'd want for no more apart from your charcoal grills. https://www.weberbbq.com.au/barbecues/p ... -built-in/
OR THIS:http://lifestylebbqs.com/wp-content/upl ... oaster.pdfhttp://lifestylebbqs.com/
Weber Australia make BBQs for LPG and Nat Gas, they will bring the grill to your place, assemble it and then install it too.
Anything goes wrong, you're covered with a 10 yr warranty and the techniction will come to your place and fix it.
Anyway, there is a smaller model to this one but this is the king of the Weber Gas grills.
Wok burners need a lot of power to get the heat up to the wok.....you'll need a triple ring burner for this, normal BBQ side burners aren't usually powerful enough to handle woks properly.
Anyway...now that I've spent all your money
(love spending other people's money
) I'll let you browse these websites.https://www.beefeaterbbq.com.au/barbecu ... Built%20in
Anyway....I'll leave you to browse at your leisure sir....enjoy and hope to see you become a part of the forum.