This has been covered a lot in this forum.
Is 28 too old to do it by Modular means or should I just bite the bullet and take the integrated route.
You can do a modular course in the same time as you do an integrated course, that is if you plan correctly etc.
What method of training do employers generally prefer?
Neither, as long as you have the qualifications/experience airlines are not bothered with who you train with. Don't get the idea that if you train at Oxford or another reputable school you will have an edge over other applicants applying for airlines, you won't.
I'm not a professional pilot, i've got all the answers from this forum, just try searching next time.