EVA Air offer premium economy as do Cathay, Thai have it on certain routes, Singapore Airlines will have it next year.
The Middle Eastern airlines avoid it to keep the differentiation between business and economy. With the big 3 M/E carriers, economy is usually pretty decent as long as you avoid the 10 across B777. I like the QATAR B777 with 9 across seating.
Unfortunately the price difference for P/E can be considerable, an exit row seat may be better value. On SIN - LHR BA premium is a similar price to Sri Lankan business class. A daytime flight on a quality airline in an exit row seat with sector times of less than 8 hours and a nights break in between on longer routes shouldn't bother most people.
Aer Lingus allow an upgrade to the economy meal for a small supplement