738
DD
The 800 when delivered was fitted with 186 seats, since then it has had the new acro seats fitted.
All 189 of them, that is from the company paperwork and not a spotters forum.
The 738 will do Egypt back to the UK (any airport from my experience of operating it to Scotland.) even in the height of summer, reasonably comfortably, the limiting factor is almost always the take of performance. But in the many times I have done it, I have never seen a tech stop or a reduction in payload. And that is with a full airplane and an outside temperature of +40 degrees centigrade.